Yes, Wings & Wheels sells the Tool-Tech rigger I referred to. I can't
speak to its use on a flapped wing, as Standard class machines were all
I rigged. In use, the only force from the trailing edge grip would
occur if the wing tried to twist or slide out of the holder. For a
flapped machine you'd definitely want to know if the grip extended far
enough forward to bear on the top surface of your wing. I have heard
that minor modifications are planned for the Tool-Tech rigger - maybe
this is one of them, you'd have to ask Tim Mara.

For me, horizontal adjustment is important. Udo's rigger uses brass
inserts riding on a square shaft, while the Tool-Tech uses linear
bearings on a rod. The Lewis Loader proved to me that metal on metal
makes it hard to adjust precisely, so the linear bearings are a
definite plus. Also, the Tool-Tech appears to offer a larger horizontal
adjustment range than Udo's, which is also useful to me.

As you can see, I've pretty well made up my mind on the Tool-Tech. FYI,
there is another rigger available in the USA, the WingMate from Chip
Bearden. Check out his site:
http://members.aol.com/wingstand/alternatives.htm Be sure to check out
his link "Other Ways to Do It" for additional input on pros and cons.

-John

P.S. - I don't know the M&M model - do you have a link?