The V (Android 15) community version became available for the Fairphone 3 (and FP4 and FP5) in the meantime (yesterday or today). I was able to upgrade from e-3.0.4-a14 to e-3.0.4-a15 through ADB sideload in the /e/ recovery, see Week 29, 2025: Development and Testing Updates - #2 by urs_lesse
I recommend to trust Manoj, not me.
UPDATE:
Only just noticed that there is a community build for the new FAIRPHONE 
now as well 