As MDM pointed out, there's no real mathematical difference between contributing a dollar directly to a Roth retirement account vs. contributing a dollar to a pre-tax retirement account and then converting a dollar of pre-tax savings to Roth.
In general the way to minimize your taxes on a long-term basis is to keep your marginal tax rate as consistent as possible from year to year. If you have every reason to believe that your RMDs will be more than your current income, you might consider doing Roth conversions every year up to the top of your current 12% tax bracket. This will serve to reduce your eventual RMDs, and therefore minimize the chance that they'll go into the next higher tax bracket. Another benefit of doing this is that when you go on social security your marginal rate while taking social security will actually be higher than your tax bracket in many cases due to how social security income gradually transitions from being untaxed income to being mostly-taxed income as your other income increases.
Also since you have no immediate plans to retire, and you expect to have more than enough money saved up when that eventually happens, I want to make sure you're aware of the option of
qualified charitable distributions from your IRA. Once you turn 70½ you have the option of making charitable donations directly from your IRA, up to $100,000 per year, and these count toward the amount you would otherwise need to withdraw as an RMD. These donations are excluded from your income rather than deducted in the itemized deductions. This can be more advantageous than simply withdrawing the money and then donating it for a couple of reasons. First, if you wouldn't itemize but for the charitable contributions, you get the full tax benefit of the standard deduction
plus the donation, rather than losing out on the benefit of whatever portion of your donation (and other itemized deductions) was less than your standard deduction. Secondly, because these qualified charitable distributions are excluded from your income they don't touch your AGI at all. This may cause less of your social security to be taxed, among other things.
Finally, I know you enjoy your job enough to keep doing it for the foreseeable future. Have you considered asking for whatever parts you find least enjoyable to be removed from your job description? You have a position of strength here. Worth a try to use it, right?