YES, I did solve this post as I was writing it. YES, I am still going to post it. THE PROBLEM WAS THAT THERE WAS A CHESS TABLE IN FRONT OF MY THRONE. This does not prevent people from using the throne, but during the bestow ceremony they need that spot apparently.

Relevant snippet of logs below. The link has the entirety that got uploaded.
First, I am playing with mods, but even after I disable literally all mods and start this quest fresh to do the bestow ceremony it still does this, so I don't think it's the mods. Also as the title says this is 1.5. If I was playing on 1.6 I would upload these to a more official source.
When I tell my royal to begin the bestow ceremony, he just idles. Nobody else reacts to join, they just keep doing whatever. He just sits there, frozen in time. I let the game run for ~12 hours (in-game) and he still hadn't moved.
Searching around this seems to be somewhat of a known bug, but I'm not seeing anything about these logs specifically. I have tried calling the bestower in multiple times and each time he freezes. Even when I do the "cancel ceremony" and call them back later it does the same thing. Even when I remove all the optional spectators it does this.
In the bottom right you can see Grump idling. In the bottom left you can see that he is trying to attend the bestow ceremony. In the top left you can see the bestower waiting.

Failed to find a spectator spot for Rofro
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Unay
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Grill
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Prosecco
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Herc
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Dani
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Marty
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Lion
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Rofro
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5837199) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Isarita
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Lynx
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Gillespie
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Prosecco
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5837443) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Rofro
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5837531) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Wingman
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
Failed to find a spectator spot for Rofro
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5837775) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5838023) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5838272) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
(Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 39)
More in depth log message about the TryMakePreToilReservations().
TryMakePreToilReservations() returned false for a non-queued job right after StartJob(). This should have been checked before. pawn = Grump, curJob = BestowingCeremony (Job_5837036) A = Thing_Human922515 Giver = JobGiver_BestowingCeremony [workGiverDef: null]
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Warning (string)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.AI.Pawn_JobTracker.StartJob_Patch1 (Verse.AI.Pawn_JobTracker,Verse.AI.Job,Verse.AI.JobCondition,Verse.AI.ThinkNode,bool,bool,Verse.ThinkTreeDef,System.Nullable`1<Verse.AI.JobTag>,bool,bool,System.Nullable`1<bool>,bool,bool,bool)
Verse.AI.Pawn_JobTracker:CheckForJobOverride_NewTemp (single,bool)
Verse.AI.Pawn_JobTracker:CheckForJobOverride (single)
RimWorld.LordToil_BestowingCeremony_Perform:UpdateAllDuties ()
Verse.AI.Group.Lord:GotoToil (Verse.AI.Group.LordToil)
Verse.AI.Group.Transition:Execute (Verse.AI.Group.Lord)
Verse.AI.Group.Transition:CheckSignal (Verse.AI.Group.Lord,Verse.AI.Group.TriggerSignal)
Verse.AI.Group.Lord:CheckTransitionOnSignal (Verse.AI.Group.TriggerSignal)
Verse.AI.Group.Lord:ReceiveMemo (string)
RimWorld.LordToil_BestowingCeremony_Wait:StartRitual (System.Collections.Generic.List`1<Verse.Pawn>)
RimWorld.LordToil_BestowingCeremony_Wait:<ExtraFloatMenuOptions>b__7_1 (RimWorld.RitualRoleAssignments)
RimWorld.Dialog_BeginRitual:<Start>g__InnerStart|38_0 ()
RimWorld.Dialog_BeginRitual:Start ()
RimWorld.Dialog_BeginLordJob:DoButtonRow (Verse.RectDivider&,bool)
RimWorld.Dialog_BeginLordJob:DoWindowContents (UnityEngine.Rect)
(wrapper dynamic-method) MonoMod.Utils.DynamicMethodDefinition:Verse.Window.InnerWindowOnGUI_Patch0 (Verse.Window,int)
UnityEngine.GUI:CallWindowDelegate (UnityEngine.GUI/WindowFunction,int,int,UnityEngine.GUISkin,int,single,single,UnityEngine.GUIStyle)
I've only been camping in a tent three times as an adult. I heard some interesting things. Never anything ur am legend worthy.
One was a bachelor's party. Some of the folks got into some things, I didn't partake. I was super anxious about the trip already. It was in the southern most part of the Appalachian mountains. Honestly probably not really even in the mountains. Maybe more in the Blue Ridge area. Anyways, it's quiet. I hear a weird noise. I immediately recognize as a helicopter. With no other sounds and being surrounded by hills and trees they sounds WEIRD! You can hear them from way further. It sounded so ominous. I jokingly turn to the group and ask "Is that the trumpet?" Implying the trumpets that will sound during the rapture. I think I sort of got a few of 'em before they realized what it was!
From that same trip I remember finally being in my tent alone. First time being in a tent alone. As a kid I always had a buddy in bot scouts or parent. I was so fucking cold. I forgot a mat to put my sleeping bag on. As I'm laying there cold, cold as hell, trying to not panic about being "alone" (because my friends are so close! Just in the other tents!) I just hear the wind. Again, in the middle of a quiet forest with only the wind creeping along my imagination takes over. I imagine it as a giant air serpent creeping along through the trees, weaving and rustling all the leaves.
The last one was with my wife for a friend's birthday party. We hear leaves crunch near the tent and hear little sniffs by our heads outside the tent. Based on the sounds I think it was a racoon or a opossum. So cute!
The other time we went camping was with my parents. They were in their RV and my wife and I just slept in the tent outside lol. It's the only time we brought our dog camping. She was such a good watch pup. Just sat on the bed, very alert. I think she was nervous. If she could talk she probably has weird stories about that night. It's interesting to think that all the noises you hear at a large campsite with RVs that you know are just folks doing stuff probably freak the dog out. She doesn't know. Even if she does, she knows she's supposed to protect us from people. Or at least thinks she does.