In the Settings > Estate area there is an Estate Planning Panel for each spouse that includes a field for Percent of Retirement Account Assets to Spend
If set to 100%, retirement accounts will be fully spent by the time you reach your maximum age. If set to less than 100%, unspent retirement account assets will end up in your estate. This setting applies to assets that aren't annuitized or used to meet Required Minimum Distributions (RMDs).
Examples
If you had non-Roth accounts only, if you set this to 0% you would in effect see that only RMD withdrawals are made and the unspent residual account dollars would be left in the estate.
If you had only Roth accounts, if you set this to 0% you would make no withdrawals because Roth accounts are not subject to RMD.
If you have a combination of Roth and non-Roth, MaxiFi will try to withdraw that percentage from both Roth and non-Roth accounts given the RMD limits of the non-Roth. If you set this to 0%, you will take RMD only from the non-Roth and nothing from the Roth.