Something I'd like to see improved is the ability to write to multiple tags of the same name to a single track via the script. Currently, one writes to a single tag with a unique string of characters between each value (e.g. val1#!#val2) which can later then be replaced with \\ using an Mp3tag action to split into multiple. Preferably this wouldn't be a two-step process, but be possible via the script somehow.
A simplified example:
json_foreach "tags"
json_select "name"
set "tmp"
outputto "tmp"
sayrest
outputto "tmp_genre"
ifoutput "tmp_genre"
say "#!#"
endif
sayoutput "tmp"
json_foreach_end
outputto "genre"
sayoutput "tmp_genre"
We use | to write to the same tag across different tracks, but there is no way to write to multiple tags of the same name for the currently processed track as far as I know.