That would work as a plan, yes.
If you want to refine it, try thinking about it in terms of the tax rate you are paying vs absolutes of "I won't reduce ACA subsidies no matter what." It can be quantified.
Before age 62 with planned income of 200% FPL (~$34.5k family of 2), if you do a $1000 Roth conversion you will pay ~$150 extra in ACA premiums for the year, $100 in Federal income tax, and maybe $x in State income tax. So $250/year plus state for an effective tax rate on the conversion of 25%+ (250/1000.)
It is perfectly OK to reduce ACA subsidies if the alternative is paying more than 25% on IRA withdrawals / Roth conversions / RMDs later.
From 65-67 - Say you are in the 12% bracket. 12% is less than 25% by a significant amount.
You could fill the <= 12% bracket(s) and the 22% bracket and still come out ahead vs the 25% tax rate from previous years. That is ~$200k of AGI for MFJ. In theory you could even fill the 24% tax bracket (AGI of ~$350k) and come out ahead, although this will impact Medicare premiums (also acting like a tax, albeit not as severe as the ACA impact.)
From 67+ with SS, you will be in the 12% bracket but still have some headroom. Small-ish Roth conversions will be taxed at 12%.
A few larger Roth conversions for 3 years (65-67) will go a long way towards not having a $5 million IRA at age 80.
Those could be 60k-ish in size to fill the 12% bracket or 160k-ish size to fill the 22% bracket. Decide at that time based on how big your IRAs have grown -> bigger IRA means do a bigger Roth conversion.
Then 4 more years of small-ish Roth conversions (30k +/-) until RMD starts at 72. Can do some Roth conversions still if RMD doesn't fill the 12% bracket.
For the duration, enjoy life. If you do pay more tax later at age 80+ it is because the markets have done well for you and you haven't had to worry about money at all for decades. I'd pay that happy tax every chance I got.