Does having a separate on-call really shield the devs from support? I assume in most cases on-call would need to escalate or reach out to the devs for issues and for that someone needs to be reachable on phone off hours?
My experience was support during business hours as part of my job as a software engineer. I used to hate hearing the phone ring, and it was rarely if ever a problem directly related to what I was developing. I felt like it was just a huge disruption to my work.