Just dealing with Dell about a Latitude 5520 wjth extended warranty.

External displays turning off and on again and system freezing up all the time even after reinstall. And Dell says it’s because of wear on the USB-C ports that is barely visible and not covered.

I did something similar. I used Proxmox and then installed PfSense as a virtual machine. You might want to look into OPNsense and PfSense. There are addons for both that do the same as AdGuard and are free and open source. I had good experiences with pfBlocker

Geekbench is pretty useless for actual performance comparisons.