Certain MDM apps support using the Play Integrity API to ban using non-Google-certified devices. Some MDM apps simply don't know how to successfully create a functional work profile without Google Play being automatically installed in it which can be worked around and we can provide an easier way to deal with it. Work devices should really be separate devices provided by the company instead of them managing a work profile on your personal device though.
It's worth noting AOSP and GrapheneOS have both drastically changed since Android 13 on the Pixel 4. GrapheneOS is based on Android 17 since June 2026 and soon Android 17 QPR2 in December 2026.