Ok answer me this because i don't know latest state of play.

In Mach if you break a tool you can pause, fit new tool, reset the offsets and carry on.
Now at one time in EMC as it was called you couldn't do this .
Les Newall of Sheetcam fame altered the program, changed it so it would and sent the code in.

To my knowledge and it's not current this still has not been implemented

Biggest problem with the development committee is they are programmers, not machinists and if they can't see a use for a feature it doesn't get put in.

Now someone will tell me yes like Les you can alter it but end of the day 99% of the uses just want to be button pushers.

The problem with geeks is they don't know they are geeks.