They stole the idea from GrapheneOS and shipped a barely half-baked version with hardcoded time. GrapheneOS has configurable time for it since years
They went with 2^32-1 milliseconds or about 49.7 days.
We don't talk enough about Microsoft's strong legacy of security innovations, IMHO.
The minimum on GrapheneOS is 10 min and the maximum is 72 hours. It can also be disabled.
The system only reboots once it has been locked for a particular duration. Setting it to 1 minute basically says: put the system into a more secure state (e.g. purge unencrypted memory) and ensure that it is ready to go when I next need it. That said, while it is not unrealistic it would be problematic since accidentally letting the phone lock (e.g. input timeout) would result in a time consuming reboot.