Well as far as generic Marlin functionality is concerned there are no Robo code changes between v2 and v3 that actually do anything to Marlin In fact there is a post around here about a DIFF of the two and lack of anything useful added. Feel free to try it (the DIFF) yourself if you are curious. In fact throughout all of the R1 firmware versions that are "stock" there is nothing that really is a variation from the default Marlin behaviors for that release (whatever release it is -- 1.0.x for R1). They have not even done much of note in the R2/C2 firmware. They have done more with the RoboOS (Rasberry Pi) side, but not so much for Marlin. The M206 will not do what you need for the autolveling. If you are manual leveling then sure that will solve it starting too low, but it will not be used in the autoleveling logic/calculations for the level plane. Just so you know (not in Marlin 1.0.x using ABL). Remember M565 is not really a "Z" offset it is an autoleveling Z offset for the probe (Set Z probe offset) and in this case the probe just happens to be the nozzle. Here is the doc: G29 Auto Bed Leveling (Marlin) Marlin 1.0.2 and earlier provides three options for automatic bed leveling The 3-point method probes the bed at three points to produce a matrix, adjusting for a flat but tilted bed. The planar grid method (non-Delta) probes a grid pattern to produce a matrix by the "least-squares" method, adjusting for a flat but tilted bed. The bilinear grid method (Delta only) probes a grid pattern to produce a mesh, using bilinear interpolation to adjust for an uneven bed. Marlin 1.1.0 and later allows the bilinear grid (i.e., "mesh") method to be used on all types of machines, not just deltas. This is the recommended leveling method going forward. Also in Marlin 1.1.0 and later, the PROBE_MANUALLY option allows all forms of Auto Bed Leveling to be used without a probe. The procedure is similar to that of MESH_BED_LEVELING (see below). Begin the process with G29 to move the nozzle to the first point. Adjust the Z axis using G1 or your host software. Send G29 again to move to the next point and repeat until all points have been sampled. Notice how the only thing gained with this (on NON-Delta machines) is a compensation for a flat, but tilted bed .