Using setopt WARN_NESTED_VAR option gives a bunch of warnings. Nested variables could be easily defined with typeset -g.
Just pushed up branch fixes/warn_nested_var_opt (PR #275) that I believe fixes this.
Does that fix the issue for you?
Apparently, some errors are still persist.

That's strange. Can you confirm the sha you're using is 8064a6f?
Yes, I can confirm. I am also getting this error like 500 times for a prompt about this line.
_zsh_autosuggest_get_bind_count:2: scalar parameter bind_count set in enclosing scope in function _zsh_autosuggest_get_bind_count
@ericfreese Just in case you don't know. You should also use typeset -g for nested variable assignments. It won't make it global if it's already defined.
@kutsan Ok, pushed up another commit 256293c that I think should be better. I'm basically adding typeset -g to everywhere that I am assigning to variables that exist from an earlier scope.
Thank you! It's all gone. Besides WARN_CREATE_GLOBAL option, I think using typeset -g gives better readability for the code. Since, reader can understand that, variables are from outer scope.
You can close the issue as you wish. Thanks again.
Merged into develop. Will release with 0.4.1