I have this set in my .vimrc for now to work around issue #1:
let g:SignatureIncludeMarks = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
Now when I try to set a mark via m, vim logs the following errors, and no marks are set:
Bugfix for issue #2 #2
Temporary placeholder for issue #1 #1.
Added function SignatureRefreshDisplay to correct the display for Signs
Can you give it a try now?
Works great now, thanks!