The AWS plugin will automatically add the aws_prompt_info to the RPROMPT of the shell theme. The Avit theme currently sets RPROMPT effectively removing the plugins feature of adding itself to the prompt.

As seen by the snippit here, the plugin sets itself to pompt.

But since the theme sets RPROMPT, it will override this. What I think should happen to keep the compatibility is to change the following line

to

__RPROMPT='$(vi_mode_prompt_info)%{$(echotc UP 1)%}$(_git_time_since_commit) $(git_prompt_status) ${_return_status}%{$(echotc DO 1)%}'
if [[ -z $RPROMPT ]]; then
  RPROMPT=$__RPROMPT
else
  RPROMPT="${RPROMPT} ${__RPROMPT}"  
fi

This would allow plugins to add themselves to the prompt without having to add RPROMPT overrides in .zshrc or to edit the theme file directly.