Bladder in the hard tank gets steady air pressure pressing on the bladder for an even fuel flow.
If the bladder material is too thick it may not get enough pressure build up to squeeze down the bladder.
A fine thread NV help get closer to peak rpm without risk of a lean run no matter what the fuel delivery method is.
High pressure setups thrive on a fine NV thread as small adjustments can make a big change.
I only use hard tanks and have and excellent results with easy starts and good idle.
All about proper prime and starting with a loaded fuel line. I like using clunk tanks even
on 1/2 oz tanks. After filling the tank and plugging the feed line to the carb I use a fuel bulb
and force fuel / air into the vent line it forces the feed line to load up removing any air bubbles.
Only takes minimum prime to start the engine and a loaded line keeps it running with no hiccups.
I only use spring starters for TD .010 and .020 and a 12v Hornet 1/2A starter for .049 thru .15 engines.