The 401K is just tax deferred so that needs to be taken into account in the math. Taxes will have to be paid at some point. I wonder if the rate could actually be higher when you retire and the way I understand it, you have to start taking money out at a certain age.
Backdoor roth ira took me several days to figure out and about a week to execute. But once you have all the accounts set up it and taxes figured out shouldn’t be too hard to repeat. Hopefully doing it again this year will be easier.