I will always sell brokerage to do either Roth or trad IRA if it helps the current tax picture, with the expectation that I will also be able to manage taxes on the back end during the withdrawal phase. I don't have experience with backdoor Rothing but taxation is a prime driver of my strategies. I don't ever expect to pay cap gains tax. Of course, a lot depends on portfolio size. Multimillionaires have different goals than I do.
Like achvi, although I fill my iBonds bucket with new money, I wouldn't sell at a guaranteed loss in order to essentially guarantee breaking even over the long term in real terms. I see people front-loading half a decade of iBond gifts as overreacting to recency bias.
.