OpenMPT's visual appearance has hardly changed since the old pre-open source days and even less since the start of the OpenMPT project. It's usable and it's fine. But I think it's going to be a major improvement if the UI was rewritten to allow for a sleeker, more modern look, including more ways to allow for customisation, especially allowing for dark mode colour schemes implemented all across the interface. More scaling options would also be highly appreciated, especially for high DPI modes such as 1440p, 2160p and otherwise above 1080p; at higher resolutions many things in the interface can get quite small, unless there are system-wide scaling settings dictating otherwise.