Collective.taxonomy - Is it possible to programatically add/update 'Terms' to taxonomies and control the 'term identifier/key'?

I'm using collective.taxonomy and I wanted to know if its possible to create a term programmatically and control the key or term identifier instead of getting a generated value.

I was looking at the where the taxonomy can be retrieved and there is an add function. When I try to test it in an upgrade step that I can re-run:

from zope.component import getUtility
from zope.schema.interfaces import IVocabularyFactory

def testAddTaxnomy(context):
    vocab = getUtility(IVocabularyFactory,'collective.taxonomy.assettypes')

it ends up existing (I call inverted_data and generate a simple vocabulary, and it was there) , but if I go to the utility control panel to edit the taxonomy, its not present. Also, I'm not sure how to use to insert it as a 'sub' term.

The reason I would like to is to have more control in an upgrade step so I don't have to make a large xml file where I can set the 'termIdentifier'.