We do this as well. Use-case: we have 7 "customer segments" within are targeted account list. In order to identify which leads/companies are part of the appropriate customer segment, we have 7 smart lists aligned to each customer segment. It's much more reliable to use email domains (using the format "@company.com") rather than actual company name (since there are so many variations/misspellings of company names). That being said, we either copy/paste the updated list into the smart list. While not automated per se, it's not too difficult at all. Not sure how much simpler this can get.