I am glad you are working on this. I have also thought about using a carb that has mid range adjustment.

I have had great luck with a VP30 and a Slimline pitts on the 1.6FX. Because the pump is somewhat adjustable you can use that to set the mid range.

Low - idle needle
Mid- Pump
High - Hight speed needle.

It may be the case that the turbo jet is making it harder to get the mid range?

I have herd nothing but good things about the Cline, but have been fully satisfied with the Perry pumps so I have not tried one.