Having the ability to natively override the velocity/rapids much like feedrate can prove useful for testing new gcode programs and macros.
I have only found the suggestion to basically change the axis settings as part of macro(s): https://forum.cncdrive.com/viewtopic.php?f=2&t=2478
I see this as a workaround and diverges the ability to interact with the settings in a normal behavior, prune to mistakes or loss of original settings.