Hi Rob.
I do not have a tool changer either. I intend to do it manually. It seems EstlCam is capable of generating a multitool gcode.
I have a auto tool zero macro which seems to work fine, and came with a audio file as well with a lady that says 2.0 complete. Quite creepy. I feel like in the movie Alien.

ˇˇI do not have a tool changer, and the code Estlcam generates is M05 (stop spindle) M00 (stop machine) and then M03 (start spindle).ˇˇ - do you use any macro for this m5, m6 in mach3?