Yeah, I mentioned the troops just as an illustration of capacity.
I think being able to load 15 troops instead of the absolute minimum to capture a base would be a nice feature, especially when dropping in a hot zone ( Maybe a perk ordinance? ) . And if you really want to get your hands dirty, program for a demolitions squad that can destroy some buildings ( structure/time, possibly ) and allow a team of those to be dropped with the troops.. to ensure that any last minute building that pops up before capture can be destroyed. Or.. drop the demolition team separately before dropping the regular troops.
Primarily, though, speed and additional cargo capacity would be the draws. Perhaps allowing C54 to carry 2 or 3 pallettes of airfield cargo as opposed to the C47s single pallette. This would allow faster HQ/Airbase resupply.. And, a much larger target for the goon hunters out there.
I took a look at some of those you mentioned. They certainly would be interesting.. especially the Messerschmitt giant, but I don't think their performance would rate perking them.
Also, the Short Sunderland and Martin Mariner would be good choices for flying boats, too.. but, again, their performance isn't worth perking.
Oh.. how about basing flying boats at the ports? Then you can add all the nifty Japanese floatplanes and make the ports even more formidable.
It's only 1s and 0s.. how difficult can it be, right?

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