Our car loan is at 2.1% and we've decided to create a "taxable offset" account for that 2.1% loan and one other 4% loan. Payments for both are $593.57/month which is not a cashflow issue.
Once the taxable offset account hits the principle balance on both loans we'll reconsider our strategy. Both loans have a low enough interest rate that we have decided money in the market is a better choice for us.
What you describe is also the most optimal way to manage a fixed, low interest rate mortgage. Unfortunately, OP has made their "long story" too short and has not provided enough information. Maxman, it is generally not good form to start a thread and then ignore it. Maybe it's not a real question, but a plug for the above-mentioned robot advisor. From their website:
"And as mentioned above, there’s another way to have more than $10,000 managed free under Wealthfront. After becoming a Wealthfront customer, refer friends to their service. Each new signup grants you an additional $5,000 of free management."
OTOH, there could very well be some other very good reason, including zombies.