We still don't know how good is the FTL in the Apple controller; all the devices are still too new and haven't been dragged through the coal as all the other controllers. It is still in the "easy job" part of it's lifecycle, with brand new flash cells.
We are getting too deep into irrelevant things. We don't know how much of Anobit IP was used in M1 macs; they may own it, but they might not use it all. They purchase their NAND and it may be not compatible with the current gen, just like when it was not compatible with Samsung's V-NAND/3D TLC.
In practice, the I/O performance of M1-based Macs is comparable to random PCIE 3.0 NVMe drive. (I'm typing this comment on M1 MBP, I'm well aware how it performs).