When loading and unloading filament, there is no cancellation-button. Also i have not found any way to move the filament just a little.
When unloading filament, i have had the filament stop due to the end of the filament being a small blob. i have then removed the ptfe tube from the extruder driver side, but the blob is to far in for me to reach with my cutters, so i need to feed the filament out a little. Being able to do this with either loading and then cancelling, or by manually feeding a little bit would be handy.
I am not sure if this is something we could potentially change ourself, i have not dove into the marlin side of the printer, but if someone would add that functionality, that would be neat.