Switching to "unstable" via sudo eopkg ar Solus https://packages.getsol.us/unstable/eopkg-index.xml.xz, which upgrades to the 5.6.4-152 kernel fixes everything.
So, the "solution" to this post—i.e., installing a custom kernel—is "although it's not impossible, there's no wiki or 'how-to' about it, so don't."