Answered Creating a level bed

Shim the bed.
Manually leveling (actually, tramming* is the correct word) the bed is done and you are really done. You do not need autoleveling (but can still use it).
All of mine are manually leveled. I still run the autoleveling on some (mostly the delta, because it is 60% math and 40% witchcraft so I am leery about turning it off). However it is not needed. Sometimes you get an non-flat sheet of glass on the larger beds and that can also be helped somewhat by autoleveling, but generally I just don't use it. Or at least don't depend on it.

There are in the newer flavors of Marlin some different versions of the autoleveling logic that are better, but non of the Robo machines currently use that by default. Regardless if you have a manually leveled machine it will work better and more repeatably.

*but that is a different discussion

 

alot of people use a hole puncher to get a circular paper disk and shim between the magnets. This works but if you life the bed they fall out. On my R1 series I use adhesive back spring steel shims- they are a bit expensive but they stay put. You can always shim under the blocks that hold the bearings for the y axis, all your call.

 

It depends When I am shimming the bed I use paper. In some cases I am actually shimming the mounts for the bed to the case (which is well under the bed) and for those I used shim steel. That is a rather more permanent fix, but not all of the inconsistencies can be eliminated with those shims.