Mortgage vs Additional non-match 401k vs Taxable Brokerage (7-10 yr timeline)

Curious for any input on the below strategy and the next possible move in the following scenario. Runway before downshifting career/house downsize at age 47 of 7-11 years. From now until then, planning to contribute up to 401k match, maxing 2 Roth IRA’s, and maxing HSA. About 800k in retirement accounts already, emergency fund well funded, no other debt, no brokerage account currently. Question is with any income beyond what is mentioned in the plan above, do we take a shot at eliminating the mortgage (3.18% & 200k balance) in anticipation of downshift… or add more but non-matched to the 401 (up to the ~19k max)… or create a taxable brokerage account and invest. Given all of our net worth is in the stock market (minus the emergency fund), and the fairly short time line, we’re leaning towards the mortgage but open to input on the other options.