Other threads in this forum are ended with the suggestion to model it with 3 line items in the advanced inputs.
- - Tax Deferred
- + Tax Free
- + Other Expense (for taxes)
- The tax rate that should be used
- running out of funds in Tax Deferred - causing the + Tax Free to overestimate the amount in savings.
I have had to spend considerable amounts of time trying to guess what these numbers should be to avoid the issues and get a reasonable level of conversions over a multi-year period. Especially when I change the retirement year, or change the amount of 401k contributions, this becomes very difficult to keep up to date.
This may not be a perfect, or even good, solution , better minds can chime in!