This is something I've thought about before and I'm still not sure I understand how it's beneficial. If I tax loss harvesting just because I can, am I really gaining anything? Sure my income for the year is lower but if I'm simply rebuying similar funds (bot not the same) at a lower valuation then I will have to pay more capital gains in the future when I eventually sell them to spend that money. In an environment where my income is closely controlled due to the ACA, having more capital gains per share is not necessarily a good thing. Ultimately I could find myself in a situation where selling the funds I need to live on triggers a bigger gain than I'd like for my income to be at.
It seems like a good tactical tool though. For instance, we'll likely have $1600 more in rental income than I anticipated since the rent for January will likely be paid in this calendar year. Our income is already at the top of the ACA subsidy bracket we chose so this pushes us over. I can harvest $1600 worth of losses to offset this income. This is a better option for someone who is FIRE than contributing money to a tIRA.
Are there other considerations I'm missing, specifically for a FIREd person?