The new meta is Power Profiles Deamon: https://gitlab.freedesktop.org/upower/power-profiles-daemon/-/blob/main/README.md
Otherwise you should see if power management is enabled for all your pcie and input devices (using powertop for example). If you run a nvme ssd, make sure it is allowed to use all power states (bit more involved topic).
Good luck :D

If you have an android phone, plug it into the macmini via usb, connect to wifi and enable usb tethering.

Probably AMD Geode based. That Tablet is just old :D