Currently, when I add a row to specify per product shipping, the state field only allows one 2 digit state abbreviation. I'd like the ability to specify a comma separated list.

The shipping scenario I have is based on zones to allow me to set up a flat rate shipping. Each zones consists of multiple states. It'd take my per product shipping table down from 49 rows to 4, making future updates efficient.

This same thing comma delineated list could apply to country and postal codes, too.