not even relevant.
it's unlikely you will ever print at 0.05mm on an fdm machine.
Plus they're pretty much guessing anyway :-)

Most printers are 'technically' capable of 0.05 layers. They are all using the same motors. Stepper drivers make a difference, but the hardware is usually - technically - capable.
0.1 is doable, and as low as you're ever likely to want to go :-)