Hi @BradM,
To comment on your last point:
My experience is using a level to get a good horizontal potision of the frame is fine. And once it “looks” level, it is good enough. In any case, a fair top beam level will not warp the workspace distances.
But adjusting the sprocket 12 o’clock to a known exact position with the level will make a significant contribution to the MaslowCNC acccuracy through the entire workspace as shown in the above color diagrams.