

Even just being rooted on the stock Pixel rom is a fight.
That, I can see being more of an issue than an unmodified, trusted 3rd party OS. If I remember right, rooting makes the device fail Verified Boot:
It establishes a full chain of trust, starting from a hardware-protected root of trust to the bootloader, to the boot partition and other verified partitions including system, vendor, and optionally oem partitions.
https://source.android.com/docs/security/features/verifiedboot
And yet split tunneling and LAN access, combined with killswitch, are still broken on Android but work on Windows.