Oh that's simple: I don't have them.
I set up this boundary really early in the hiring process. I sell 8h of my day and I'm not reading/responding/doing anything else outside of them.
If they want me to, they can issue me a phone/laptop and I'll install whatever they want me to, but I'm not going to look at it outside my hours unless we negotiate paid overtime.
So in short, never have work accounts on your personal devices. If you need a reason to refuse that, you can always go with "I don't want to be held liable in case someone steals my personal device and gains access to your company's secrets".
I don't actually know if there is a form of mobile device management just through a Google account, but if so, I would be careful. Some companies route all traffic through their VPNs, Firewalls, they might install certificate for deep package inspection etc.
There is a reason for such measures, but they can compromise privacy.
Aside from very few exceptions, I would also advice companies not to add private phones to MDM. Phones are too cheap to take the risk.