Hi @Kartug, thank you very much for contacting us, and for your detailed feedback.
The behavior you're seeing is normal, but can be improved.
PlasticSCM is a DPI aware application, however Gluon is not.
That means, that when you open PlasticSCM in your 4K monitor, you can see it perfectly. Unfortunately, PlasticSCM does not support (yet) per-monitor DPI scaling, so when you move the window to the 1080 monitor, it gets blurry. If you want to see PlasticSCM fine in your 1080 monitor, you need to first move the window there, then close and reopen it.
However Gluon is not (yet) a DPI aware application. That means that is optimized to be displayed in a 100% DPI monitor. When you open it (or move) to a higher DPI monitor, it's blurry.
We'll try to improve high DPI support in the future, so thanks for your feedback.
Best regards,
Dani