My first time nuc building thoughts...

[LazyBkpr]

   I like feeding nucs from the top. I made "lids" just for feeding.. the lids being used on the  Michael Palmer style nuc are actually for a standard 5 frame nuc, but still work well, just a bit of an overhang. The lids also let me feed from the opposite end the entrance is on.
    I have two division board style feeders. I used them once, I wont do it again, at least until I have made the modifications to them you already mentioned.    I have seen good results with the hive top feeders.. the type that have the floats for the bees to walk about on.

[apisbees]

All the different ways of feeding have their good and bad points. what you choose and use will depend on your style of beekeeping. some like in hive and keep them in all year and then they are there when needed and extra equipment is not needed to be brought to the bee yards. Some years during blueberry pollination the bees will starve if not for the intervention of the beekeeper and providing emergency feed. With having the feeders already in the hive it is easyer than having to take and place feeders on each hive before feeding. In hive feeders can be moved over next to the cluster and act as a division board also.

[riverbee]

ed, i like and use 1 gallon pail feeders over the inner cover of a deep, and cover it with an extra box.  my nucs, like scott, have secondary lids also that i can use an inverted mason jar or the pail feeder.  for me the pail feeder works better when i move nucs away, i can strap the whole works down to a pallet so that wandering critters can't knock off the feeder or the lid from the nuc.