A point is a terrible unit for displays. No point in attempting a solution when ‘px’ is a viable solution already. Use ‘px’ where you can and then use ‘pt’ for your print styles.
If points were actually points, I could use a 12pt or 14pt font on both displays and be perfectly happy. I'd still have to deal with how it changed the number of available columns, but that's a solvable problem.
If you need to scale up the terminal text to read it, don't you still need to scale up the other parts of the UI, so you can see those too?
On the Mac at least, it seems to me this stuff works reasonably well. You can set the overall scaling per-screen, and you can set the (scaled) font size used by the Terminal. It's really not clear to me why you'd need to change both the UI scaling and the font size on a particular screen.
Love me some pointed puns