OP,
At 50 yds it will be fine more than likely regardless of FSB or receiver style used.
Rifle length vs carbine length. Geometry! Sight radius comes into play. The detachable carry handle aperture wasn't tall enough for some to shoot accurately on carbines at short distances. Main reason Colt went to F stamped taller FSB was to zero a flat top receiver on a carbine length gas system / FSB at 25 yards. As stated some shooters had to crank the post nearly out of the FSB to zero. Now F stamped FSB is the mass produced most popular cost effective product and is installed on most any thing AR, necessary or not.
Longer rifle length sight radius will zero regardless of FSB height and zero distance on a fixed carry handle or flat top upper receiver. Colt never had a problem using or zeroing the fixed carry handle upper receivers with carbine or rifle length barrels A-1 or A-2. Problem occurred with the introduction of the M-4 flat top carbine in mid 90's with shorter 6/3 detachable carry handle. Matech flip sight will zero with either style FSB. Main reason question was asked whether you were building a carbine or rifle.
Again generally the problem only occurs when using a flat top receiver and detachable 6/3 carry handle shooting very short distances. Of course if a taller sight post or taller FSB is necessary to make a 25 yard shot by all means have at it. On flat top rifle with F stamp FSB the sight post is simply lowered in FSB an additional amount to zero and until one starts getting into 600-800 yd shooting it's seldon pertinent.
Regardless you need to build and shoot it to see if it will zero or not. Not much available today without the F stamped FSB pre installed on a barrel assembly but there are exceptions. Only in retroland where it's all about the small details would anyone even care to look at a FSB. Authentic retro rifles didn't have F stamped FSB's! Although some had a F casting, which are rare today and has nothing to do with 0.040 extra height. Thinking it's on the GM flavor FSB but may have been the H&R and definately not Colt.
For example I have 3 older build flat top carbines with standard height FSB's and at 25 yds all will zero with standard sight post remaining in the FSB with anyone but a novice / newbie at the helm.
Easiest remedy for a non F stamped 25 yd elevation zero problem is a 0.040 longer sight post. I bought a 0.040 sight post from BM when problem became apparent for some and have yet to need it and it resides in it's original package even when using 6/3 detachable carry handles.