一方面，Trump tax cut到2025结束，税率可能上升，所以要做ROTH conversion，最好2025以前做。
The BBB legislation packed another double whammy specifically for Roth accounts. Starting in 2022, the bill had proposed to end so-called non-deductible backdoor and mega backdoor Roth conversions. Regardless of income level, you’d no longer be able to convert after-tax contributions made to a 401(k) or a traditional IRA to a Roth IRA.
An additional rule had aimed to prevent Roth conversions of any kind made by anyone making more than $400,000, or any couple making more than $450,000, by 2032.
Both are free software inculding detailed Roth conversion strategies as well as other major parameters for retirement planning.
Roth conversion is under "Additional Inputs" then "Cashflow Type".
Actually this is better than marginal as you could set up tax rate any way you want like adding a persentage for your state tax. On the other hand it would need more specific input to simulate your situation.