Random application crashes and full system freezes across multiple different systems

I am deeply confounded by this topic.

Nothing make sense - you said the Clevo wss the most important system.

I run two laptops and 2 desktops on Manjaro unstable branch.

I suggest you pick a system, backup data you cannot be without.

Perhaps execute [root tip] [Utililty Script] Backup configuration and package list to have a backup of packagelists and configurations on external media.

Since all your systems are encrypted - I would take one system at a time - first testrun the system using live ISO.

You can even create a custom ISO beforehand - to have all the applications you use - jetbrains toolbox is easy - everything exist in .local and .config.

Long uptimes is not a problem if it is server without gui - but long uptimes for workstations and laptops are in my opinion a bad habit - long uptimes may cause weird issues, memory buidup or leak - a lot of things can cause freeze and crash on desktop system.

I am thinking it must be the combination of software - perhaps AMD system need to define amd pstate in kernel commandline - but it really, really difficult to suggest what you can do.