well between the 6 hole and the butterfly (now my new standard) you don't need anything else.
Once you have something that works - why keep looking for other stuff
Different world to braiding where there are pretty much always issues with every design. Get a good leather pouch, attach cords - sling works perfect every time.
Plus after playing with davids flat pouch slings - I will NEVER use anything but a shaped pouch again.
First time in my slinging 'career' I've ever had release issues. Bloody things are a nightmare.
Rather than deluging people with a variety of different pouches - just stick to one or two that are known to work.
The six hole is great for denim of other thinner/weaker material pouches. And the butterfly is perfect for leather.
Each can be made any size. Just covers the whole gamut.