I know uccnc is unitless, however I was wondering if G20 + G21 could be added to the available list of Gcodes so that they could be used to toggle a checkbox (or LED) which could then be used by macros to check for metric or inch correction for meters / min or, inch per minute or feet per minute which can be applied within the macros directly by users.
Note this is just a checkbox (or LED) toggle, we already have G50 + G51 should you wish to rescale the gcode.
G20 / G21 would do nothing other than toggle the checkbox or led unless you had a macroloop or macro which was looking for the status of that checkbox or LED within the screenset (general settings tab).
Thanks,