Hey there, @redbigfoot.

I appreciate you coming back and letting us know how those steps went for you and your business. 

I can see how beneficial this could be for your business. However, there isn't a way to force QBO to reliably honor the custom rate. 

I suggest submitting feedback to our Product Developers so they can consider this as an option in the near future. 

Review our Updates site to keep up with what's new in the system. 

I hope this helps answer your question. Wishing you and your business continued success!