Will you have two pensions of $50k each, or one?
A rule of thumb often espoused here is to figure out what your tax bracket would be once you are taking SS and subject to RMDs if you made no conversions. (You should probably also make that calculation assuming that one of you has died, and the survivor is filing single.) Then you could plan to convert up to the top of that bracket now.
Beyond that, I cannot tell you best practices, but I can tell you what we plan to do. We are in a somewhat comparable situation (but I have more in tIRA/403b, and less in Roth than you).
I plan to make fairly aggressive Roth conversions between now and 2025. Why 2025? I am assuming (for the time being) that the tax laws will not change, and so we will revert to higher rates in 2026, so I want to get my conversions done before then. ALSO, I am the same age as you. I will turn 63 in 2026; this is significant, due to the 2-year lookback for Medicare IRMAA rates. The upshot of that is you do not want income in 2026 that will put you into a high(er) IRMAA tier once you turn 65 (which is based on your income in the year you turn 63).
Another question to ask yourself is: How much (if any) money do I wish to leave unconverted in the tIRA/403b? I plan to leave ~$500k there for two possible purposes: large medical expenses (which are mostly offset in income by a tax deduction), and charitable contributions. In other words, there is no sense paying taxes to convert money that will later be used on tax-deductible expenses.