You're not alone. Sync for Reddit would even let you switch accounts temporarily while posting a comment. Though, oddly, I dont think it displayed which account was currently logged-in before you made the switch.
I would often use the temporary login feature even when I thought I might be logged in as the user I wanted to comment as because I needed to be absolutely sure I was using the right account.
I had a very extensively curated feed but I was only a lurker. But I'd made a separate account for actually posting something some years later, so I'd use that feature to post from my "public" account to the account that had the good content
And sometime later I had made a 3rd account for a different reason. And I don't believe you could see which account you were currently on before switching. Often I'd start posting and forget which one I was on, so had to use that option to make sure I was posting from the correct account
Use different themes for each account make sure the accent colors are distinct and that's how I've solved so far
Thunder has this. 
๐
Welcome to the official Sync for Lemmy community.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
1- No advertising or spam.
All types of advertising and spam are restricted in this community.
Artwork and community banner by: @MargotRobbie@lemmy.world