You are correct LF, the lens is undisputed winner no matter what I can come up with in terms of reflectors. Greengenes posted his reflector test results at 12" distance he gained 30-40% across the board (with a CXA3070)
The 200-300% figures I showed were at a 16" distance on Vero 18s, so large gains were expected because I would never try to run V18s bare at that distance, but that is the distance we needed to get the correct spread with the lenses on. So a more fair test might be, lenses off at 8" vs lenses on at 16", assuming I was still getting useable light in the same amount of canopy. Also, this is without the benefit of reflective walls. I did the test with almost no reflective assistance from the surroundings, so in a small reflective tent the gains would not be as high.
As far as COB mounts and which reflectors are compatible, unfortunately I have no knowledge at this point. I filed it in my head as "later on down the road it will get sorted out but right not availability and compatibility is all messed up".
@Greengenes707 took the hit on that one and ordered a bunch of stuff to check compatibility.
@Positivity has figured out a bridge as well.
Myself, I have been just kapton taping-on a few light weight plastic DIY reflectors for now wherever needed. I have added a few short reflectors to the flowering modules on the outside edge of the canopy. It definitely gets the job done in the short term, but I expect that we will figure out a way to securely mount 90-120 degree lenses and maintain a small air gap between the lens and COB.
The optic lighting modules have magnets bolted to the lens and they stick the the steel on the housing. Very cool but of course magnets do not stick to aluminum or copper so that doesnt help us bare heatsink DIYers.