I just ran a M48 probe test on my Ender3V2 CR Touch and it was repeatable to 0.01mm or 0.0004". Good enough for me.
RobM - The procedure for the bed levelling with the probe is
:go to prepare
:Go to Manual levelling, Turn on probe, click on centre (you only need to do this once)
then click on each corner and work your way around. It will tell you how far above or below each corner is from the centre. Adjust each corner as you go to get it as close to the centre as possible.
It will take several times around to get it close but .01mm is quite doable. A caveat to this is the repeatability of the probe. If you probe isn’t repeatable then your levelling will be off.
0.1mm (0.004") is probably good enough, less is better.
This is basically the same as paper levelling but more accurate because you use a probe (BR or CR Touch)
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