I haven't seen the Higley book, but I'd be curious about the mod myself. I just flew my Mini for the first time last weekend, and as everyone said, it's a blast (but it does balloon under power). I built the N-struts per the plans, but I beefed up the plywood blocks (they're basically glued to the wing sheeting). Assembly/disassembly is time-consuming, but part of that's because the plane draws a crowd at the field.

The only other mod I made is replacing the wire landging gear with a Hangar-9 .40-sized aluminum gear. Stronger and better-looking, IMO.