Hello,
Since I started using Linux, I've noticed that everything is too small on the login screen. Once logged in, I configured the desktop with a scale factor of 200%, but I would like to apply this setting to the login screen as well, right from startup.
For your information, I am now on Zorin OS 18 and my screen is a 4K TV.
I'm not sure but you could try it with gdm-settings. Follow the guide for ubuntu 24.04.
You can set a scaling factor for the font at the login screen and at tab display you can set "Apply the current screen settings"
I tried it on the Zorin 18 live boot stick. The first method didn't work for me, only the second one with adding the ppa. But I couldn't test it with the loginscreen.
I also tried the flatpak of gdm-settings which worked to install.