How many bits a particular NAND chip can store per cell is presumably hardware-level, but I believe it's possible to achieve SLC on all of them anyway, even if they support TLC or QLC.
Hell, the Silicon Power NVMe SSD I have in my machine right now will use SLC for writes, then (presumably) move that data later to TLC during periods of inactivity. Running the NAND in SLC mode is a feature of these drives, it's called "SLC caching".
Hell, the Silicon Power NVMe SSD I have in my machine right now will use SLC for writes, then (presumably) move that data later to TLC during periods of inactivity. Running the NAND in SLC mode is a feature of these drives, it's called "SLC caching".