So I actually performed the emitter transplant tonight. I unsoldered all that mass of wiring and removed the mcpcb. I was kinda surprised to see no sign of thermal compound under there. Its even fully anodized:

Terrible thermal control there, but I guess this little light isn’t driven hard enough to need it? Not sure, but its at least getting some thermal compound before I put it back.
My first swap was with one of my new 90 CRI 219c’s. Turns out the Zebralight driver doesn’t like it at all. The light comes on in sort of a medium mode, with some flicker. Any sort of switch holding or double-clicking causes the emitter to pulse a little, but not actually change. I can only assume the low Vf of the 219c is messing something up, but I don’t know enough about the electronics to say for sure.
So I pulled it again, this time swapping in a 219b:

This one works great! Its not as bright as the 219c would’ve been, but that’s okay. I love 219b’s anyway, and so does this Zebralight apparently. It’s alive!

Its also still disassembled, because my fasttech lens order hasn’t arrived yet. But the hard part is done!
PS: Sorry for the bad photography. All I had handy was my cell phone.