i cant seem to get the dimension blacklist to work. ive tried a return separated list and a comma separated list. and neither seem to work

Currently the blacklist takes in the world names and not their id's (this is being changed in the next version to accept either or). Use return to separate your list elements and you should be golden.

So.
Overworld
Nether
End
Should work?

Lower case and I think it's the_end.