I personnaly see the categories (products; partners etc...) as proposed by Odoo as a rigid solution; this is more for accountants or It specialists than for business.

To be convinced, see how the integrated website deals with the categories of products: it makes the assumption that potential customers share the same understanding as the one proposed by the web site. This doesn't seem to be the right way to give the market an opportunity to buy your products.

On the contrary, giving the possibility of identifying products or services through efficient searching capabilities, namely based on multiple tags or labels is a way to drive the customer.

Not to speak of enriched answers provided by SPARQL searches and answers which could lead to new opportunities.

Have you looked at this module? It allows you to add tags to your products.

product_tags 

It may not offer the tags in the POS though. I don't use the POS.