rebar controls aren't the easiest to work with vertically, so I had to make some concessions, e.g. the name of the property is now shown in the cue text (and part of the infotip)
I've just installed the beta and it works. I see the limitations you mentioned, but the idea is good. I think the vertical layout makes more sense as it organizes the search steps from left to right, although this might be a cultural bias. I don't have a high DPI monitor, so I can't give you feedback on that.
I'll stick with 'horizontal' or regular layout for now.