Thanks for posting the mod! I’ll try the highFeedrate change. Really strange on the M25. Are you feeding from an SD card? One worry with using M0 is that the wiki says that it disables the steppers. This can cause a displacement and loss of origin if they are paused between full steps. Also you really want them locked while changing the tool. What do you see happening with M0? I could be reasoning the out badly because I have not looked at the code in a long time.