Key element to “not paying the fine” is to be certain you have no tax refund coming. The only collection provision apparently is deduction from a potential refund— and the “fine” being imposed for either not reporting you are covered, or reporting you are not covered. If you don’t report anything— well the letters start? who knows.
Yep, someone pointed out that the law doesn’t forbid garnishing wages to get the special tax ($90 or 1% the first year) but if very many people don’t comply that would be impractical.