"Easy and cheap would be to put some swept back handlebars but it would compromise the fold a bit."

Roger that.Some of the Vitesses have a telescopic h.bar post and a h.bar clamp. They are easy to mod with MTB type riser bars with a couple of inches or so of lift. (30mm or 50mm)

Then they can be rotated back or forth to extend or reduce the reach. You need to check the clamp diameter first.

They can be cut down to size with a rotary pipe cutter, from your local plumbers merchant. Sample:

Easton EA50 Riser Bar | Chain Reaction Cycles