...as well as a double lever arm setup as a single (see saw) lever would pull instead of push. I'm still trying to work that out in my brain. Flexibility and space availability are pointing me in the direction of a qev.
This is probably the reason behind the way 3DBBQ designed the current trigger on the B&B.
I've built a few TMG's, and attempted to build a Dyne myself, and I concur getting the trigger right without destroying your finger seems to be the hardest part. My first trigger used an allen wrench of all things and it worked really well, the only problem is sore fingers(and it wobbled around like crazy; it was pure jank). You can think of it like a safety, since you cant pump it more than 3-4 times and still be able to reasonably pull the trigger. My subsequent triggers used 8/32 threaded rods, a nut, and a faucet seat. its reasonably comfortable when you don't go past that magic 4 pump number. with that amount of pressure, you get pretty good fps, and anything more just destroys darts anyways.
I couldn't get the Dyne I built to work like 3DBBQ's for a similar reason(pumping enough for more than 1 consecutive shot makes it impossible to pull the trigger). It may be due to the fact that he used what looks like a brass ball valve, and I used a pvc version, and possibly his has more air volume between the ball valve and the second check valve. I'd have to build a second one to test that out.