I remember someone saying that those are patch files, we're not getting full firmware so there's no way to downgrade.
Found it viewtopic.php?t=198168#p1031333
You can see huge heatsink inside AXLite. I was surprised how heavy it felt, then I just looked inside the case.Have a look at casings of AX2 and AXLite.
Plenty of openings for thermal management. That's for a very good reason.
You can go to fcc.id/TV7L41GXD and look at Internal Photos.You can find one disasembly of Hap Ax lite on YT and there you will see, that there is a space for soldered modem.