HiDPI mode not working for external 2k (2160x1440) screen
 

I'm using a Dell D6000S docking station with a Macbook Pro M1 14" (2021 model, running Ventura). I have two external 2k screens (Dell P2720D) attached to the docking station via DisplayPort, which work fine. I've been trying for ages to get some proper display scaling on these, which MacOS for some strange reason refuses to support on anything that is not a 4k display.

I was very happy to see the "experimental HiDPI" feature in the new version of DisplayLink manager. However, when I enable it, nothing changes in the MacOS Display settings menu--I can still only select the actual resolutions supported by the display, and doing so changes the actual driving resolution.

What I want to achieve: drive the screen at its native 2160x1440 resolution, but have everything in the UI scaled up by a factor of 1.25 or so. (Just as is possible for the macbook's internal display, and also very easily with any screen on other OSes like Windows or Linux w/ Gnome etc.)

There are some other tools out there to help with this MacOS limitation (e.g. "BetterDisplay"), but they unfortunately only work with natively connected displays, so not with screens connected through DisplayLink.

If the DisplayLink Manager is able to help me out here, now or in the near future, I would be extremely grateful! Anyone any ideas/suggestions?