Don't know if this has ever been brought up, or even a problem for anyone else, but I would definitely like some failsafe put in place for this. I am creating walls for large complex OSR dungeon crawl maps for the game I am running. The knot placements get to be quite numerous and time consuming on these massive maps at times. Sometimes taking easily a half hour or more for 1 section alone. I get in a rhythm and go for some time. Then, oops, I have to remove the last knot as I didn't place it in the right spot. I swing my mouse over to 'Remove Last' and click the button, but low and behold, I either went a little to far with the mouse, or it jumped, and poof......I click on the 'Manipulate' tab just above the 'Remove Last' button. I then end up throwing my cordless mouse across the room with some very colorful expletive's as my work vanishes before my very eyes. This has not happened to me once. Oh, no. that I would get over quickly and move on, which I had. No, this happened 3 times now and the waste of time having to redo this work is getting ridiculous. There must be a way to prevent that from happening when in the middle of working on things like this. If you got this far, thank you for taking the time to listen to my rant.