It shouldn't (and doesn't) double count the entry. Unchecking the"I'm self-employed and bought a Marketplace plan" box delinks the 1095-A from a Schedule C.
Regarding TT accuracy, the 1095-A seems to be an ongoing source of issues. There were more serious bugs with the handling of 8962 and subsidy repayment limitations in both of the last two years that could result in taxpayers significantly underpaying. I raised the issue with both Intuit and the IRS and it was eventually acknowledged but not fixed before April 15.
