I would also like something like this. A shortcut key and/or button that you click and it will automatically use the value in the copybuffer for the ID. (Both for MB and Discogs.)
Even if you aren't able to pull it from the clipboard buffer I would find it extremely useful if it accepted a full URL and just stripped out the junk it didn't need.
For instance, I would like to be able to just enter this:
Instead of having to just copy the 66b1a283-08e3-4096-b4b6-38bb8cba30ab into that field.
That would be pretty cool.