I picked the xp-l hi 5000k. This means you can run any battery you want. Might be swapping in Samsung LDs in but if you wanted high CRI the Nichia and SST-20 require you to use a battery that has a low current, 10A, and 20A respectively. The 219B is a rare led, so it was tempting, but the cell depenance seems scary.
This is simply not true. A Samsung 40T for example can safely run the SST-20 version. Between the voltage sag and peak amps an SST-20 can support it simply will not be in too much danger. The 219B you might want to be a bit more conservative but it could easily support 20A.
I didn’t check FireFlies website since they added new pictures and the pictures in OP and the one contactcr put in his message weren’t showing. My VPN is blocked and can’t access FF’s website.
I don’t like this protruding boot and the press fitted retaining ring doesn’t make the change easy so I will probably not buy it despite my “interest” for the Cu+Ti if there is no option to have the old one mounted.