Hello @Harrisonp,
Welcome to the Community. Thanks for sharing detailed information on your concern. Glad to know that you're loving the new Automated Sales Tax feature.
Regarding your concern in the second company, please note that once you disable this new feature or switching to Manual Sales Tax, there isn't an option to switch it back. Refer to this help article for more information: Switch to Automated Sales Tax.
You may want to consider looking for a 3rd party app that works the same way as the Automated Sales Tax. Simply go to the QuickBooks App Center and search for a keyword such as Automated Sales Tax calculation to get started.
In the meantime, I'd suggest you manually enter or change the tax amount calculated in a sales transaction. Refer to this article to learn more: Enter the sales tax amount manually.
Let me know if you have more questions. I’m always here to help. Take care.