As I am laying out my system, I have 5 PRIs on the first floor and 2 in the basement. My goal is to have 3 of the first floor PRIs as interior followers, but be instant when armed stay. I am going to set the remainder as perimeter along with the door sensors. Basically when I arm the system as stay I want everything to be instant. Is there a way to do this?
If I am understanding, unfortunately no, you cannot do this.
Interior Follower is a zone type which is only armed during Away mode, and does not trigger alarms during entry or exit delay.
Keep in mind the only local difference between “Stay” and “Away” arming is the arming state of Interior Zones. If you want motion detectors active, say, when you go to bed, and plan to disarm remotely before walking past a detector location in the morning, there is nothing wrong with arming “Away.” Some Alarm.com rules also can play off of arming status, but they are optional.
I do not typically recommend it, but motion detectors can of course be programmed as perimeter instead, but note that they will be able to trip the alarm during entry/exit delay that way, so you would have to remotely arm/disarm out of view of the detectors each time.