There sure are a lot of options to get a good little thrower. I got a UF-T20 mod'ed and that's a nice option as well - it's a high quality zoomie, if you would want to go that route. It's about the same size as a C8, maybe a little smaller than the XinTD, with a true glass aspheric lens. Here's my post on the T20 build:
https://budgetlightforum.com/t/-/17005#comment-354207
I got 75 kcd measured, but with the dome. Now I can reliably de-dome (using gasoline), did several now 100% success, so could probably get 150 kcd out of this light.
Can't go wrong with modding a XinTD though. For the V4, I'd up the amps to 3.85A (mod the stock driver), re-program the driver to have any set of modes you want, add copper to the inside of the pill, upgrade to a SinkPAD or Noctigon copper star, change the emitter to a XM-L2 U2 or XP-G2, depending, and de-dome it. In theory should get about 95-100 kcd out of the XM-L2 U2, and higher with the XP-G2, just not sure how high - maybe 120-140 kcd. It already has a nice AR lens, nice brass pill, good tailcap switch, and can re-use the stock driver.
Edit: Oh - I'm certainly not the only one that can do these mods - there are quite a few guys capable, many more technical than me!! I do like publishing the results though, using my lightbox and light meter - it really puts it into perspective with actual measured results.