Hey guys, thanks for the input and ideas.
Just updating for closure, never had any luck with this and definitely not recommending anybody try the manual choke Revolution carb for sale at the website I listed above. The guy selling them had good prompt communication and tried to help. He was successful with the carb on his Urban Express NU50's which are exactly like mine and same year, so maybe I just got a bad one.
He sent me a smaller idle jet, which made a very slight difference, but still was never able to get the bike to rev up unless I completely unscrewed the top cap and pulled out the throttle slide completely. Tried with the #78 main jet that came on the carb (which worked the least terrible), the main jet from the stock NU50 carb which I believe is about a #85, and then with #71 and #75 main jets from treatland. No luck. With each jet combo, started with mixture screw out 1.5 turns, but with each jet didn't matter if turned all the way in or all the way out, zero effect.
All ports from the oil injection were capped off and I checked all around with starting fluid so there were no vacuum leaks. Float level and valve on carb operational. Plenty of fuel flow from newly cleaned tank and new fuel line and filter. Just bbq'd the exhaust and it's flowing great and reinstalled with a new gasket. Verified needle properly properly sliding into valve and tried with it the circlip at each height setting. Zero difference there. Verified no plugged jets and that throttle slide was going from all the way closed to all the way open. Again, no luck unless it was completely removed along with the top cap.
At some point you just gotta throw in the towel, so tomorrow just gonna put the stock carb back on minus all the autochoke/bystarter garbage and just go back to running the stock carb. Main reason for "upgrading" was to avoid the bimetal garbage autochoke system in the first place with the revolution's manual choke but to hell with it. Going from 25mph to 16mph isn't an upgrade and if I ever feel like I'm missing out with no choke, well that's why God created starting fluid.