I'm going to have a small batch (like 10 or so) fabricated in aluminum and cerakoted black. The plastic version works great and locks up tight, but if you want to take it on and off a lot to use the folding stock I think it's going to fatigue over time. So I reckon I'll run the prototype for a little while and then I'll put some money into an aluminum versino.
I still have to see what the fab costs are going to be but since I'm making them for my own use either way, I'm not looking to make any money off of it, so if folks are interested I'm happy to ship some out at shipping cost. I'll post in this thread when they're ready.
I'm also happy to share the CAD file for folks that wanna fab their own.
It does make a night and day difference in feel and immediately finding a nicely repeatable 90-degree trigger press for me at least.
EDIT: turns out fabrication cost isn't too bad at all, so I'll have 10 anodized black aluminum versions of these AXSR plug-and-play thumb shelves in a week or two ... I'm going to keep 2 for myself and then I'll make the rest available for anyone who's interested here at shipping costs.