Add an “undo” button to mobile when adding topo markings to photos

I pretty much only use my phone to view and add content to MountainProject. This includes drawing topo markings to photos.
It would be nice if there was an undo button while adding markings. It seems ive often made a small error on a single marking and then had to completely start over.

It would be nice to have a quick “undo” option to remove the last action(s) then continue drawing.

No problem if this is a pain to add. It would just be a nice option for creators.

Thanks for a rad site!!

Noted! I was actually curious if mobile web browsers have any keyboard function or workarounds and didn't find anything. We're doing work on the topo building tool so this could get incorporated sooner than later. Thanks for flagging.