Your assumption that v24 was not tested on multiple display systems is incorrect.
Many users and testers (including myself) have multiple displays and do not have the issues that you have. (As I said above, I found most of my scaling issues went away when I switched my main display to the external UHD display that I run SketchUp on.)
However, other bugs and features that also needed fixing were fixed. Should the Trimble SketchUp team have held back and not released those fixes that benefit everyone ?
They are not ignoring these display issues. They have priority. However, the bugs are in the 3rd party Qt GUI libraries and are outside of Trimble’s control.
One of the SketchUp Dev Team members has said (somewhere here in the forum) recently that the Qt project is aware of these problems and are working on them. This means a cycle of testing in the external library project.
Then afterward a cycle of testing by SketchUp because updating dependent libraries must be fully tested so that they don’t cause other unforeseen major issues when deployed.
It is the nature of software engineering that fixes just do not come as fast as the end users would like them to.
Ranting, making incorrect assumptions and throwing blame is the wrong directions does not help the fixes come any faster. But it might (subjectively) make y’all feel better.