Most of the time I do not want to take the additional time to re-run bed level calibration before each print. It does not change so that is a was of time. Because I am using Orca Slicer I just leave the checkbox in the print dialog unchecked. The problem is, there are times when running the calibration needs to happen and I sometimes forget to check the box.
I think that most of the conditions needed bed level calibration to be run can be identified and then it could happen automatically.
I am not sure how much of this can be done in just the slicer, but in combination with the firmware it is not a complicated feature.
Identify all the times when the bed should be leveled before printing.
If any of the conditions are true then automatically add bed leveling to the start of the print.
Conditions that I know of that (probably) require the printer to run the bed level calibration.
After a failed print - any print that is stopped before completion
after the printer has been power cycled. This is based on my belief that the printer does not save bed calibration across power cycles
after a firmware update
when the plate type is different from the previous print
I run bed calibration every time I remove and replace the plate, unless I’m printing a small part.
In terms of enhancement request I would prefer the firmware to have a “quick check” where it it checks the back corners (it’s easy to place the plate on top of the corner stops) and perhaps 3 points that will be covered by the print. If those are within tolerance then move on, else perform calibration.
In terms of calibration, it would be great if it would only calibrate the portion to be covered by the print. I suppose the complication is that the calibration is stored so if the next print covers a larger area some decisions need to be made about how to proceed.
I do the same as you mostly. I’ve found that if I can remove the part and purge lines without removing the plate, then the machine does just that on the next bed level. My machine does a 5 point check (4 corners and one off centre) It looks as though it’s comparing the points to the bed mesh it has stored. If any point is out of spec, it will restart the bed levelling and do all 25 points. Sometimes I can remove & replace the plate without it needing to redo everything. I find the magnet on the bed to be very strong when the bed is cold, and when you drop the front part of the plate it sometimes moves the whole plate as it drops. This sometimes causes one of the back corners to be on top of the white corner guides. I now bend the plate when installing it, to allow the back 1/3 to be stuck flat already then I push it back into the guides.
Most of the time I remove the printed objects as soon as they finish printing. I have not had problems if I remove the plate and put it back. Much of the time I just hold the left front corner in place and lift the right front corner and that pops the object loose without removing the plate.