There is an up and coming company TuneMap supplying Liner notes, Photography and a whole lot more on artists. I have posted this in another topic post.
This may not be the answer to us being able to edit & customise Bio’s & Reviews but it could be used under license by Roon and this may be a more complete solution for mainstream or well known music & artists but when coupled with “Editable Bio’s & Reviews” which would be for the lesser known and obscure Artists & Music would be nirvana and solidly builds what Roon bio’s & review part of the app started.