having spent way too many hours on roth tools and studies, its seems a 50/50 split for roth and traditional IRA is a decent strategy in light of all the unknowns. (given similar investment options in both. there is chance the work you put in has a non-zero chance of retro rule changes.)

one caveat are stealth taxes like IRMAA and 'investment' tax, which fly under the radar of public complaints and thus increase exponentially and pass fairly easily in congress.
also, many forgot to include weighted probabilities for non-spousal inherited investments; even if roths, they have to be whittled away over 10 years into your taxable bucket.

since i have a lower income window visible via early retirement, i will try to get a 50/50 split before medicare, but no anguish regardless:

current trad:roth 8:1
shift ~25%/yr for 3 years into roth (based on available cash for taxes pre-conversion)