Primary Vocab instead of Primary Term

A new feature could be a select form for vocabularies instead terms. In the database vid would be the only data stored, the tid would be superfluous.

A draft:

• In content type config, the configuration would be the same: a list of checks for select the vocabs of the content type, and a check for this behavior (vocabs instead terms)
• In node add, a select with the vocabs.
• In node edit, the vocab if exists would be selected in the select form.
• Tokens would be a value for vocab vid.

Is it a good idea?