You do not need to change the CS even when all your data is stored in one different CS. Projecting to LL always does work lossless for AIM. In many cases, you will also be successful re-projecting data in an individual CS in AIM. But this depends on the CS you selected and on the input data as many CS have just a specific area which is valid. So here, you will face unexpected behavior in some cases.
You also cannot change the model CS afterwards, so once you run into such an problem, rebuilding the model may become necessary. Therefore we suggest not to change LL if you have no intend to work on the SQLite file directly or of cause policies. That way you will stay flexible for whatever data you will add in future.
Heiko Meyerdirks
Senior Manager, Engineering
AEC Design-BID-Infrastructure