@Ñuño_Martínez thanks for the first link, I couldn't find it.
Let's say solved.
I have branched 3.0.4 for some tests to a private 3.0.6 branch. I managed to get most 3.0.4 version return to reply 3.0.6 except that {$I %FPCVERSION%} that still returns 3.0.4.
Will have to dig/hunt a bit more.