I have provisioned my own Taxonomy Field as a Site Column. I have used a feature receiver to bind the correct Term Store / Term Set information and I have created (and bound) the hidden Note Field (and set it as the Taxonomy Field's "TextField" property).
When I add my Taxonomy Field to a document library (through the browser) then it appears to work fine. I can browse and pick terms and values and the filtering in the library works flawlessly, with one minor problem..
The taxonomy field is not appearing in the list of search refiners. In fact, if I look in the Search Schema then the Crawled Property and Managed Property has not been generated.
I have checked the document library and both event receivers for Taxonomy fields are present (for ItemUpdating and ItemAdding). The library has added the Taxonomy Catch All column and when I check the contents then it DOES contain the values which I assigned to my custom taxonomy field.
As a final check, I created a new Taxonomy field (as another site column) through the Browser and that one works perfectly (search picks it up and it appears in the refinement panel).
I compared the Schema of both fields in SharePoint Manager and they appear identical (with the exception of the field ID, field name and the TextField reference to the hidden Note Field)
I am honestly at a complete loss .. can anyone help?