You can't expect people who are knowledgeable about this stuff to just forever accept that someone asks for advice, gets told the solution, and then ignores/belittles the person with knowledge.

This is our daily life experience. We get hired to be experts, and get told by non-experts that our solutions are not tenable every single day. Only for that solution to eventually be accepted when the user in question figures out their idea was not useful and the expert was correct.

We have to put up with it at work, we are not obliged to accept it here.

Then you didn't explain the issue very well, because what you're asking for was given to you exactly. Builds also have flags, and you should know that if you're complaining about advice given to you. I'm not saying that to admonish you, just giving you the info.

The next step down is that you're using Portainer, and having user-error issues somehow. So another solution is renaming these actions something with a very obvious prefix like "BUILD ACTION", but also setting memory limits.

The very last step is making sure your swap is in order. Allocate 2x your system memory to swap, and this will help alleviate OOM issues to a point, but especially during builds.

If you come back and say this is a band-aid solution, get a better machine and stop asking questions to solve the impossible in here. This is your fault this is an issue to begin with, you don't know how to run your machines (regardless of it just being a home server or whatever ), and you're just being rude.

Those remote access fears can be solved with a wireguard VPN

I don't want to have remote access to my server outside of my home for security reasons, so this is just the bare minimum

What are your security concerns?