Follow these steps to delay the start of RMDs and manually select the age when RMDs begin:
Set up a temporary Current 401k "401k-TEMP" account with account type Roth
Set your "401k" account to $0 and move the full current balance of "401k" to "401k-TEMP."
On the Insights Savings chart, find the balance of the "401k-TEMP" at the age you will stop working.
In My Plan > Withdrawals, model a planned one-time withdrawal or distribution from "401k-TEMP" to "401k" at your work stop age. Transfer the value you found on the savings chart at that age.
Check the Insights Expense chart for your RMD plan.
Please note that the above workaround is not perfect. It will get you closer to the scenario you mentioned in the note.