I know that many UV players find troop loading very cumbersome in UV and that
they have problem(s) loading troops on transport ships in "Transport" TFs.
I never had...

This is how I do it...
Leo's "recipe" for best possible (for me) loading of troops on "Transport" TFs
#1
Write on paper the names of units you want to load. Also write how much space
they will take on ships.
#2
Create separate TF for each unit you want to load. The size of such TF depends
on available ships and other issues (i.e. larger ships are faster but they
load/unload slower - it's your choice).
The cargo space in any such created TF should be equal to or larger than unit
you want to load on it (i.e. if you want to load Japanese Inf regiment with
6900 load points you must create TF with at least 7000 points of cargo space).
#3
If there are more transport ships (i.e. APs and AKs) in harbour than what you
need put them all in one auxiliary/temporary TF. This is to stop UV to
automatically add ships to your "Transport" TFs if it thinks you allocated
insufficient cargo points on ships).
#4
Load every unit on appropriate TF (the units will start loading).
#5
Join all TFs into first one.
Now all ships are in single TF and they will continue to load their allocated troops.
#6
Disband auxiliary/temporary "Transport" TF (it is no longer needed).
This way you effectively create single TF and have all the ships load all
units you want in manner you want.
Nice and easy - isn't it !!!
I hope you will like this... this method never failed me...

Enjoy!
Leo "Apollo11"