Forced HiDpi Mode not working for 2560x1440p

Hi there,

I'm working with a hackintosh on an external monitor and want to enable HiDpi on the native 2560x1440 BenQ SW270c Monitor.

I followed several tutorials, such as:
https://www.tonymacx86.com/threads/adding-using-hidpi-custom-resolutions.133254/
https://medium.com/comsystoreply/force-hidpi-resolutions-for-dell-u2515h-monitor-5304e5506214

Essentially I've created a new Display Vendo ID Folder in /System/Library/Displays/Contents/Resources/Overrides and wrote a plist file with the help of this tool, defining 2560x1440 and 3840x2160 as HiDpi.

My plist file looks like this:

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">

<plist version="1.0">

<dict>

<key>DisplayProductName</key>

<string>Radeon RX 5700 XT</string>

<key>DisplayProductID</key>

<integer>29471</integer>

<key>DisplayVendorID</key>

<integer>4098</integer>

<key>scale-resolutions</key>

<array>

<data>AAAKAAAABaAAAAABACAAAA==</data>

<data>AAAPAAAACHAAAAABACAAAA==</data>

</array>

</dict>

</plist>

In the system setting I can now choose HiDpi und the scaled display setting, but only for 1080p.

Where did I go wrong and what is the right way to achieve 2560x1440 HiDpi setting?