As of now, artist with an ISNI just simply display the numbers (and X) as plain text but I wonder if it’s okay to link it to the ISNI website like the other external links. I don’t mean putting it with the rest of the external links but simply linking to the website probably with a copy button if it’s hard to copy the ISNI itself should it be a link.
That was supposed to be fixed in 2013, wonder what changed. @Bitmap: have a look if you find some time, if not I will check when I’m back in Estonia and working