I just posted a very similar question on the same topic.
I've been using ported and non-ported chokes with FCW equipped shells and still cannot say whether or not ported tubes have any effect on pattern density.
Federal suggests non-ported, more open chokes with their FC Wads, but I've gotten my best patterns from tight, ported chokes such as a .643" SSX and a .660" Indian Creek BDS. Both chokes are ported and have wad strippers which works in direct conflict with the FC Wad, but still delivers better patterns than my
non-ported .665" Undertaker, .660" and .670" Carlson's chokes.
I'll be watching both threads as I'm sitting on quite a stash of Federal FCW shells.