The second item was a really ugly oversized theme that I was not
able to change. This is the one that made it useless for anything
that I wanted to do. I did some hunting for a solution but the
only thing I was able to find was that others had that problem
but there was no solutionThat may be an issue, but more likely it's just your opinion on the default GTK+ 3 theme. And again, of course, there are solutions. You could have your application load in some CSS that overrides some properties to shrink padding on the elements you feel are too big, decrease font size, etc. It wouldn't be difficult.