Okay, I know the old twist the toe strap to lock it into the pedal thing, but my Triomphe pedal isn't cooperating. I bought these because they are very friendly to either cleats or not. The problem is there is a ledge below the rear "fence" that won't allow a twisted strap when riding with cleats. Any other ideas?

Make a small hole in the desired location and use a small, short, lockwasher and nut to prevent it from sliding through thee pedal's strap slot. Some have done similar by wrapping thin strips of duct tape around the strap to prevent it from sliding though the slot but I don't think it would stand up to a sharp yank.

...or a rounded off bent piece of aluminum with a copper rivet. T-Mar basic idea seems the only way out.

I'd take a small hole punch, 1/8 or less, and punch two holes in the leather that straddle that brace that meets the back plate at a right angle near the outboard side of the pedal. Then secure strap to that post with a tiny zip tie or even nylon cord.