I bought IFX4 for me A1 last year - all it needs is an installer
actually, you can install IFX manually - everything IFX needs should be in it's own directory.
Do NOT install any gadgets, libs - like the datatypes.library - or anything weird. The thumbnail lib is ok and is saved inside the IFX dir.
and, yes, you need the assign in the s/userstartup file.