I read this as a bit convoluted and wanted to confirm/clarify.

If the person is paying their own Health Insurance Premium (not "SE insurance"), and the corporation is not paying it nor reimbursing for it through Payroll, then there is no corporate involvement in that cost.

If the corporation pays it directly to the insurer or as reimbursement to the shareholder as the insured, that needs to run through payroll, and that makes it part of Gross Labor costs as a taxable fringe benefit, so it becomes part of QBI computation.

And of course this person would also get wages, because that is required.