I believe it lists and allows you to sort by the path column on the edit series editor page.
PATH IS ALREADY CONFIGURED AS A ROOT FOLDER SONARR CODE
One thought I was having though to offer this was add an expand to show detail css formatting to the warning, but I have't messed with the UI end of the code yet perhaps could offer some thoughts on such an idea. If you're missing a root folder, you probably want to fix that missing root folder issue, and that's probably not something you particularly need to know each series to address? It seems like a missing root folder would fall into the same concept to me. And as already pointed out, the fact I would end up with 100-1000 warning messages would suck. But frankly if they are targeting a mount for series, I'd assume a mount would want to be rw, and a ro would be more of an error/diagnostics issue, so a single warning would suffice.
Instead of doing a distinct on the list of series's mount path, I was thinking to show the warning per tv series so folks know what to edit/adjust in the series list if they wanted to change up the mount for a series. I also thought about this as well when looking at mounted as read only health check message.