Extend purchase_invoice_method by partner

[rpsjr]

Odoo core states the possibility of set purchases invoices methods based on products. Sometimes, the invoice methods become a partner policy question instead of products. What about extending purchase_invoice_method so it can read partner data?

The idea is to extending partner model so to register their sale, our purchase invoice methods and them make bind purchase_invoice_method when there is partner policy fixed.

Anybody willing a similar solution? Is it worth?Let's talk and discuss.