Yes, that’s what I mean - but unfortunately FP2 is NOT officially supported by Sailfish, for whatever reason… So no chance to use Sailfish, as e.g. we urgently need these days the Swiss Certificate app etc.
And I have several FP2 and will stick to Fairphone, the FP4 is waiting on my desk for the eOS (mid January).
Install one of the custom ungoogled GSI Roms from project treble. Take a look to project treble and you will discover there are a plenty of custom roms available for the FP4
probably you could provide a link? To my understanding GSIs are not Custom ROMs and so far Custom ROMs are still not officially published, even if some developer already started to build them.