It seems this is the driving force for your web interface request … a means to an end perhaps rather than having a web interface per se. I was going to point you towards this topic but I see you have found it, post and voted for it. 
Personally I think there is more chance of Roon enhancing the functionality of their app when it’s running on small screen devices rather than them developing a new browser based portal that offers functionality provided by their application when run on large screen device.
Just my view, only time will tell.