Apparently theres now an SST20 version of the BLF A6?

I think there is. I saw it here.

Huh. Well, this isn't really the BLF A6 upgrade I was hoping for... the high CRI 4000k SST-20 is a nice (in the right tint bin at least), but not a good choice for a single emitter FET light. I don't see how this setup won't kill that LED quick.

I like the idea of an upgraded LED in the A6, but I would have gone with the SST-40 5000K. It can handle FET current with no problem, would be an upgrade on output from the old XP-L HD, and it's readily available in China.

LH351D is another good option. I saw the other day that apparently Astrolux is bringing out an updated S43 with LH351Ds, so they ought to be able to do an A6 with the same LED. Hopefully they got a good tint bin... the tint lottery is real with that LED.