Would not recommend System76. I’ve had many issues with my machine (primarily software, related to their buggy custom firmware, and Pop!_OS, until I ditched that for stock Ubuntu). Their support has been terrible - rather similar to OP’s, actually. I’ve had the laptop for about 2.5 years, and I’m checking practically daily for something to replace it.
Considering that you are not using their software, was the laptop worth the premium you paid for it, vs buying from Clevo directly?
I figured the hardware and software coming from the same vendor would yield the best results, and wanted to support a company that supports right-to-repair, and Linux in general. But ultimately I found Pop!_OS buggy and had performance issues, so I’m not using their OS, and their firmware is causing issues with my SSD, so I’d like to be off of it as well (but was told "there’s no process for reverting to the proprietary firmware“ for the specific model I have). I could have bought a Clevo directly, saving hundreds of dollars, and probably had a better working machine.