Userscripts.org

I think KoC changed their code a moment ago
because it doesn't drop out of its iframe now
and the map doesn't appear extended on my browser.
.
It will still work if you right-click somewhere on your KoC game,

then select 'This Frame' > 'Show Only This Frame'
.
I'll see if I can work out what they changed.

Good news:

I slightly modified the @include line from
*.kingdomsofcamelot.* to *kingdomsofcamelot*
to make it a little bit more inclusive, and that worked.