Same on my MF-01 (very early second batch with the 6S 3P led arrangement and newer driver). Nichia, which I think perhaps run hotter.
But more seriously, I discovered that the three screws holding down the MCPCB to the shelf were loose and/or stripped. After a few hours of experiments leading me to be disappointed with (I thought) early thermal step-down on levels less than turbo, I heard a rattle in the head.
It turned out one of the three screws had come out and was rattling around, the other two were loose. Turned out the missing screw had stripped threads in the head, and the other two stripped as soon as I applied very modest torque. The screws were far too short, barely any thread engagement. The first few threads in the shelf were all stripped.
Perhaps Mateminco realised this weakness and set their screwdrivers to a very low torque to mitigate ?
After installing much longer screws everything is now as it should be, the MCPCB is firmly secured and thermally it seems to be behaving better. All levels except Turbo are now usable without step-down for reasonable durations.
I didn’t check the thermal compound under the MCPCB at the same time, didn’t want to disturb it, but I’m fairly sure it is good.There is definitely some there.
It is now a torch that I have confidence in, and is exceptionally good. I have even got used to the primitive UI.
Tip: if not sure what mode it was last left in, just disconnect the battery with a slight twist of the tube, reconnect, then it will start in ultra-low. Saves you from e.g. turning straight on in Turbo when you just want to go to the bathroom at night, or having to cycle all the way through Turbo just to set a lower level.
I also think the contact springs in the head are slightly too long, becoming coilbound before the tube is properly tightened, maybe putting too much stress on the driver board, will investigate and maybe crop a coil off them if necessary. Brass contact surfaces on the battery and driver ground ring I think benefited from some metal polish after bedding in. Witness marks suggest so. Meanwhile it is working very well