Sorry we are starting to mix two problems/issues here. @Allan_Cook could not resume cutting when a tool change is requested when using Fusion 360 generated gcode. It is not about moving Z axis during tool change which is in thread Tool Change Functionality (Question About Ground Control) - #15 by Bee
So on this issue: I can confirm today that using Fusion 360 gcode tool change the cutting operation can be resumed using the Resume button. I previously WRONGLY stated that my GroundControl version number. It work on V1.2.6.
I will post more info on the second issue in the other thread linked above.