AE inconsistent with fps & duration on imports

Does anyone know the exact rules AE uses to determine length and FPS of PSD (or similar) imports?

Most of my AE work is 15sec / 30fps so I have set Prefs to:

My experience:

When switching between projects that use different fps/length and import several different assets like PSD and sequences, I MIGHT experience inconsistency with the length and fps of imported assets.

The same goes for FPS. When I finish a 25fps project > open/start 30fps project > AE MIGHT think I need 25fps and applies it. Doesn't matter of I have my Prefs set to 30fps and the opened project is 30fps.

I just did some tests with application open, going between different projects, importing, saving, etc. All goes as I would expect (nothing messed up). But WHY do I sometimes end up with an imported PSD with Comps set to 25fps, in a new or resaved project of 30fps? Or it uses the length of an unrelated project that I worked on a week ago ago? Using another project's length as a reference in a new composition, that's not right. Especially when Prefs are set to a FIXED length!

This doesn't happen consistently tho. It always catches me by surprise. That's after using the app for 10 years.

I don't want to have to double check if it imported a PSD correctly or not. Usually I find out late, once export is already done. I'll have a stuttering result because AE imported by PSD as 25fps in my already existing 30fps project. Or sooner when PSD comp length is too short and I don't see sh** in the 2nd half of my timeline.