Dale - Post #61 here: https://budgetlightforum.com/t/-/30722. Seems the quad was in another model flashlight - not an X6. Hard to tell from your description there - not much details on the quad build, but sure makes the quad sound bad - major heat sag. I'm working on a quad (same MCPCB, same Carclo lens) for a SupFire A6 using a filed down spacer from Richard (mtnelectronics alum spacer), but waiting on better LED's to arrive. Hoping it will work ok with a DD driver. The X6 of course is a better host, but the A6 has the compact size advantage, better suited to these optics.
So, the quad setup is really designed for a smaller diameter head light with 24 mm optics and 20 mm MCPCB, but can be made to fit of course, The triple seems to be better made for the X6 because of the wider optics of 35 mm, bigger MCPCB at 32 mm.
So, you obviously seem to need to retain the lens for a X6 quad setup (optics falls short in width) and I assume the heat sink is designed for a depth with the stock lens installed. But for the triple, is the height of the heat sink designed to use the lens or not?