There's now a "Creation codes" item under rooms for GMS2 projects. It lets you view/edit CCs for all rooms at once. Mind that this is not really tested and also will not work in search and also I'm not doing a GMS1 version for it cause I have too much to do and you get what you pay for.
Fixes:
Fixed local variables sometimes not highlighting straight away after saving in GMS2 objects.
Fixed argument statusbar not showing up on func(<caret>) with no spacing