Something to think about; from Schwab's website:

The backdoor Roth may not last forever

"Although this strategy has existed since 2010, the IRS has not officially commented or provided formal guidance on whether it violates the step-transaction rule. (When applied, this rule treats what are several different steps as if they were a single transaction for tax purposes.) Experts have mixed opinions on the likelihood of this happening, but the lack of a definitive ruling means there is some risk involved. If the IRS decides that the loophole is a violation, you could owe a 6% excise tax for overfunding your Roth.

If restrictions do come into play at some point, they could require backdoor Roth converters to pay a penalty or they might include a grandfather clause. In the meantime, it’s an option to consider."