Display resolution resets after reboot

Hey everybody. So I have a two monitor setup with different resolutions, one 1440p screen and one 4K screen. I use my 1440p screen most of the time, but my 4K screen is chosen as the primary screen by the OS which results in some apps showing up really small in the 1440p screen due to DPI differences.
I kind of remedy this by setting my 4K monitor’s resolution to 1440p, but Pop!_OS does not remember my chosen resolution when I reboot my PC, it defaults back to the native 4K resolution. Anyone have an idea on how to fix this?
Alternatively does anyone know if Pop!_OS (or any other distro) has a similar multi-display DPI support like Windows? (where the application window gets adjusted when you move it to another screen with different DPI).

This is what I do on Manjaro to have my screen settings stay nice. I have a 1200p and a 1440p monitor.

*** Multiple Monitor Configuration

We can make sure displays are arrenged like we want by adding this in the *~/.config/i3/config* file:

#+begin_source Shell
exec --no-startup-id xrandr --output DP-0 --primary --right-of DP-2

*** Mouse Acceleration

If not set system-wide (see above) this can be added to *~/.config/i3/config*:

#+begin_source Shell
xinput --set-prop "Logitech G203 Prodigy Gaming Mouse" "libinput Accel Speed" -0.85

Obviously, use the correct mouse device name. :P

*** DPI settings on spiff

This one is a bit more complicated, so look at https://linuxreviews.org/HOWTO_set_DPI_in_Xorg for more info. We need to set both the /Display DPI/ and the /Font DPI/.

**** Configure Display DPI

Create or edit */etc/X11/xorg.conf.d/40-dpi.conf*.  Inside will be:

#+begin_source Conf
# Set monitor DPI (see https://linuxreviews.org/HOWTO_set_DPI_in_Xorg for details)
Section "Monitor"
    Identifier   "<default monitor>"
    DisplaySize  1224 385    # In millimeters

**** Configure Font DPI

Edit *~/.Xresources*. Change the Xft.dpi: to say

#+begin_source Conf
Xft.dpi: 110
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