To me, it was contradictory to have a Z endstop and to do Manual (Mesh) Bed Leveling, but this guide speaks of a metal arm (seek for those two words on that page) and THAT little travel distance of the metal arm is the +/- area of adjustment, so in the end it worked for me. I think I will replace that with an opto endstop, that will allow me better adjustment, I think. So that's my experience so far with this. And true, @JustSumGuy, how in the world would Marlin have an opportunity to sense the bed without an Endstop?
Other idea: Would manual bed leveling also work by placing the Z axis' only endstop on the high end of the Z axis and then go negative from there in order to find the bed at a defined distance?
Other idea: Would manual bed leveling also work by placing the Z axis' only endstop on the high end of the Z axis and then go negative from there in order to find the bed at a defined distance?
+<-- Endstop | | | Bed -------------Z^