Most folks here should know how Pistol-Forum is tied into modern appendix carry, but if you're not, it's worth digging into. What I'm seeking is a list of holster makers that, early on in this, were making AIWB specific holsters with AIWB specific features or novel ideas that help establish where we are today. Both leather and plastic, or any material is of interest, as well as changes along the way that were brought on by the changing cost or access to technology and materials.
I'll start with a few baselines...
The Custom Carry Concepts Shaggy was the first wedge based AIWB, stemming from discoveries using the CCC Looper.
The Garrity Invictus was one of the first holsters to add a muzzle feature that pushed the muzzle out and consequently the grip in.