Before I did an overhaul of my fuel system a couple of years ago, my 900 would suffer from vapour lock fuel starvation. It only ever happened on really hot days when the motor got really hot usually when filtering through heavy traffic. The engine would splutter and cough to a stop but restart on choke (obviously badly because it was already hot but it drew more fuel in) only to die over and over. The only solution was to park up and let it thoroughly cool down before it would run properly again.
After checking all the pipes and vents etc. I didn't find a definite cause but suspect it was down to the vacuum fuel tap (which you have done away with) and the vacuum fuel pump getting weak and not working as they should so, along with all the pipes I changed them both and have never experienced the problem since and we have had so seriously hot temperatures this year.
Are you planning to give the bike a run with the fuel pump bypassed?
I am not sure it will get any fuel to the carbs without it as the tank's outlet is so low but either way don't forget to blank off the vacuum pipes from the inlets that operate the pump.
Allens performance do a repair kit for the vacuum pump and the pipes are available from Motorapido.
https://www.catalyst-findit.co.uk/in...64&pid=MK-DF62