Rick,
You are not alone on the difficulty trimming this stuff. By coincidence I have spent the better part of the past two days applying Aviattic's Lozenge to the flying surfaces of the Fokker DVII (OAW) I'm working on. I'm amazed at how tough and thick this stuff is, and yet it still snuggles down over detail as well as any Decal I've ever used. I'm using brand new #11 Blades to trim the stuff however, discovering the "elastic" qualities of it with the very first piece, I'm now trimming and cutting to an "anal" degree before applying it to avoid the challenges. I've tried files and sand paper, no go!
I'd say work ahead on the trimming in the dry fit stage to reduce the trimming requirement post application. This product is definitely new to me, and I'm surprised there haven't been previous remarks on this topic.
Your wings look great; I wasn't confident enough to try pre-shading on my very first attempt at Aviattic lozenge so Il be post shading this one.
Cheers,
Lance