Another option is netconsole for kernel issues, but that requires a separate system to receive the UDP logs. This may help with suspend issues.
Regarding NVIDIA GPUs and suspend, my recommendation is to use an Intel-only system for a painless Linux experience, at least for the local system. Intel has had the best Linux drivers for an overall experience and I believe the most reliable suspend. It's possible the suspend problems are entirely due to the NVIDIA GPU. Isolating the problematic component should help you identify the problematic driver.
If I have to run a NVIDIA GPU it's usually in a separate chassis. Avoiding having to deal with NVIDIA GPUs on local systems leads to happiness.
I would recommend trying Fedora with nvidia akmods to see how your system performs with one of the latest kernels. Chances are there may be fixes for suspend and driver issues.
The zen solution is to avoid having to deal with bad hardware and drivers. Otherwise the only realistic solution is to start recompiling the kernel, file an issue with the hardware vendor, and/or stick to hardware that someone else supports to fully work with linux. I believe steam machine uses AMD GPUs, and they have had better support in the Linux kernel than NVIDIA.
Things have improved but you’re still pressing your luck…
What about SSH in to debug before rebooting? Or maybe log with the kernels’ net console feature (mainly wired Ethernet), assuming a physical serial port isn’t available