I've got two term ref fields: field_single and field_multiple.

In a list of tokens produced by theme_token_tree(), the first field's token is expandable to show stuff from the taxonomy term including the id. The second doesn't get this.

I assume this is by design because with a multi-valued field you run into the question of how to specify the multiple terms. But it would really save some headdesking if there were a mention of why this is in the UI!

Eg: make it expandable but when you expand it it just as 1 line with a message explaining why there are no subtokens.