Hey Russel,
yes, it’s the ‘max-soft-limit’ setting of the Z motor.
You can move your Z axis there with the g-code command
G0 Zxxx
where xxx is the number.
If you want to tune the code executed in your ‘tool-change’ field, see here.
If your g-code toolpath exceeds the dimensions your Onefinity can work on, you will get a warning after having loaded it.