If the mesh itself doesn't change much once the tilt is resolved, you could just load the saved heightmap rather than re-doing the mesh. G29 S1.
If you want to save a mesh to a new file without overwriting the default, you can specify a file name.
See the detailed usage of G29 here: https://docs.duet3d.com/en/User_manual/Reference/Gcodes#g29-mesh-bed-probe
If your dual Z motors each have their own driver, you could automate the tilt correction: https://docs.duet3d.com/en/User_manual/Connecting_hardware/Z_probe_auto_levelling