As far as setting up a spotter cam, you can use any camera as a spotter camera. If you see the video in BI, it can be used.
Just set up the triggers to trigger the other cam. Not hard to do in BI.
On the PTZ camera, set up a group containing just that PTZ - it should be the only camera in the group so call it PTZ for example.
In the camera GUI for the PTZ, make a preset(s) for it to move to when triggered which gives the view you want. You can have several spotter cams each triggering a different PTZ preset, but you need to set those up first.
After you are done, redo in BI the find/inspect for the PTZ to ensure it pulls all the presets
On the Trigger tab for the fixed camera, under "When triggered" select "Move to preset" and select the preset number you just created for the PTZ.
Check the Trigger camera group option and hit select and pick the group name the PTZ is in.
Then check the move camera groups and hit select and then the camera group.
Hit ok and then that fixed cam will call up the PTZ whenever the fixed cam sees motion.