I would agree with @laffisloon that if you choose a plan other than the 2nd lowest Silver plan, you may pay more (or less) than 8.5% - depending on the cost of the plan you choose. I would also point out that under current law, the 8.5% subsidy calculation is only effective through 2025. Under current law, beginning in 2026, the 400% FPL cliff for subsidies will become the calculation again.
I would point out that there is a whole section in IRS Pub 974 2022 Publication 974 (irs.gov) starting on page 47 for dealing with self-employment and the tax credit:
For anyone who is self-employed and is eligible for both the Premium Tax Credit and the self-employment health insurance deduction, it’s probably useful to go through this section to determine what the optimum solution is for your specific circumstances, since, as you say, it’s circular.
AJ