Thanks, trying it out now! One more thing; can is it possible to have this on Homebrew? Just to make sure it becomes a default app for me.

EDIT: works well with Sidecar -> Mirroring the Dummy display! Lag/latency wise, feels at least the same with native Sidecar. And thanks for the humongous amount of res options, even though I don't need it right now.

I have another usecase: I used to have an off-brand external display that doesn't register HiDPI res to Macs. Bought DisplayResX for that, but maybe this can help. Once again thank you!