Will delete if I'm wrong.
On line 32 the printer fan is turned off with an M107, but I don't see an M106 anywhere in the code. Prusa did not have any default code that turned the fan back on after a tool change, so I had to alter the gcode to insert an M106 at the end.
Oh... yes, you're correct. Good catch!!! I'll fix that in the next release.
Bill