On my rather big screen, I immediately had to zoom in because the font was too small, and most of the screen was quite empty. Storing the current zoom level or font size to survive the restart would be a comfort function.

This is a great point. I'll have a play around with adding font-size settings.

I prefer the vertical arrangement, including the addresses of the available brokers (like in MQTTexplorer), because I sometimes forget which name I assigned to each broker. Their addresses help me to remember. I think it has enough space on the screen when no broker is connected.

I agree that current tile view on the main page can cause some friction. I will explore this too when I have more time.

Thanks for the feedback and kind words, very much appreciated.