Just a thought but, are you able to configure a setup like my RANS V-Rex has. It's a pivot joint so you can swing-up the handle bars,....up and forward, out of the way. Than you hop on and pull the handle bars back towards you for normal riding.
1> Cut the stem bottom away from the handlebar clamp.
2> Got another stem with bar holder clamp.
3> Got 10" of 3/4 electrical conduit. Perfect fit!
4> Using a bech grinder, ground down the hex head of a 3" long metric bolt that fit the quill. Originally it fit a 9/16 socket. Ended up fitting a 7/16 socket. The 7/16 socket head fits down the entire stem.
5> Welded a washer near the output of the lower stem just before the quill angle.
6> Welded the 3 pieces together.
7> Using a 1/4 drive entension 14" long, I can tighten the bolt holding the quill up against the welded in washer.
Works like a champ. Without the long stem bolt it is actually lighter than stock.
A folding bar would not work because my knees would still hit them in their down position. The stem must be raised for FWD/PS pedal steer.