Been working with the notion of conditional Gcode built into the toolchange macro. For instance I might want the printer to prime and wipe the nozzle if the tool is at a temperature around standby (say >180) but will not try to prime the nozzle if the hotend is below a standby threshold. Does a conventional logic statement work for this? has anyone else tried this? Another thought is to have a system variable turned to high during printing and turned off outside of printing or once printing is complete. This way the machine won't accidentally try to cold extrude just because the prime code is enabled in your "Grab tool" or "Tool Change" script if you grab a tool trying to check your system prior to printing.
Duet Boards will not extrude at low temperatures and will report an error to the console that the tool was not driven as it is cold. At least that is what I experience.
