[jdietrich]

>What does it matter if it’s less than ideal if it produces satisfactory results?

Input shaper calibration is affected by the surface that the printer is standing on. If your workbench happens to be more or less rigid than the surface the printer was calibrated on at the factory, the calibration won't be accurate. The input shaper could fail to correct for some resonances, or correct for resonances that don't exist. This will cause visible artefacts in the print.

Other printers at a similar price point offer one-touch calibration of input shaping, or automatically calibrate before each print as part of the homing and warmup routine. On the Mk4, you need to buy an accelerometer module, figure out some way of attaching it to the printhead and the bed, then run the calibration routine twice.