I’ve got both the B74 and B74e.
B74 uses XPL-HD,
B74e uses Samsung (LH351B?)
B74 has 3 brightness levels (Low-Med-High)
B74e has 2 brightness levels only (Low-High)
One thing noted for this light is that it appears to be designed to be used with longer protected 14500 batteries (when ordering the B74 with 14500 battery included, the included battery is a protected 14500 battery with a built-in micro-USB charging port, and this makes the 14500 battery quite long (it’s one of the longest, if the not the longest 14500 battery I’ve encountered).
Given the above, I’ve tried some shorter button-top 14500 batteries (and even some regular AA batteries) — when using these more regular batteries while the flashlight is ON, then try to stick the (turned-ON) flashlight on a magnetic surface, the light has a tendency to power off or flicker — my guess is that the shorter AA or 14500 battery will get “sucked” by the magnetic tailcap while it’s getting attached to the metal surface, and this makes the positive side of the battery temporarily lose contact with the driver head portion, thus turning off the light or flickering while getting magnetically attached.