Is it safe to add custom fields directly to the Catalog Item table?

[newhand]

HI everyone~！

Main purpose: I want to add additional information to each catalog item (similar to taxonomy topics), so that I can use them as facets in AI Search.

Why not use taxonomy topics: Although multiple taxonomy topics can be assigned to a single catalog item, only one of them is indexed by AI Search and be used as facets.（I hope my understanding is wrong.）

Here are two ways .

A: Create a new table that extends the Catalog Item table.
B: Modify the Catalog Item table.

question:   which is the best pratices ?  （Will this cause issues when ServiceNow is upgraded in the future?）

NEED HELP ！！