I have had no problems installing or moving BIAB files and folders around. smirk I've always installed all the Realband/Realdrums on to a second installed audio hard drive in my my last few PCs due to the space taken. In fact all my BIAB files are now on this drive totalling around 143GB and it runs from there perfectly happily.

BIAB installers and updates always check where you want the different elements stored. And these settings can be easily changed in Preferences if you need to do so at a later date.