yes, I am using the alarm inputs on my Bullet cameras and NVR to hook up to a load of sensors, motion sensors, contact switches, door bell sensors, pressure mats, anything that needs the fastest response possible.. My Dahua NVR is configured to respond to these and tell any or all of my PTZ's to go to preset and it does it as bout as close to instantly as you can expect.
Ive got my automation and security system using HTTP API to also go to PTZ Presets but the response time is noticeably worse, mostly the Z-Wave network and http api combining.. its only a second or so, but every bit of latency adds up.
I'll be wiring another motion sensor up to the Ultra Starlight Bullet.. Its going to be zoomed in on sidewalk and up close to camera someone could walk under it in my yard and not be seen.. so the motion sensor will be there to tell my front door PTZ to check out that preset when it goes off.
here's a demo video I made long ago when I first started setting this stuff up w/my Black Face PTZ: