Since Sage100 does not offer out-of-the-box an option to calculate freight based on order $ total, has anyone found a work around?

We have different freight percentages established and would like to somehow designate a customer to a particular freight percentage (via table I guess).  And a solution that can auto-update with changes to line item qtys/prices.

I know there is a retired extended solution through Blythco to achieve this,but looking for a current solution.