I wonder if I'd be happy with one super ultra wide screen instead of two regular screens?
That was basically my solution when it happened to me last time DisplayLink got broken by OSX changes. I switched from MacBook screen + 2 * 1920x1080 screens, to MacBook screen and one 27 inch 2560x1440 screen.
Nowadays that is what I prefer, one biggish monitor above my MacBook screen (I'm one of these odd people who use their MacBooks open plugged into a second screen rather than closed with external keyboard and pointing device).
I make extensive use of keyboard shortcuts in BetterSnapTool to actually use my 27 inch monitor as if it was two portrait-ish monitors.