I don’t think the co-called ACA needed to include specific provisions for the IRS to enforce collection of Obamacare penalties.
The supreme court has defined these penalties as taxes.
The IRS is empowered to collect taxes.
They can/will most likely use existing enforcement methods to collect unpaid penalties (taxes).
Except that a law which relies on general provisions of external code can have specific cancellations of the general rule, and those specific negations will control, all else being equal. So even if the IRS would normally have all the draconian collection powers everyone is worrying about, it cannot use them here, at least not until the law is changed.
Though I do agree with others here who are concerned about accumulation. If at some future point the law is modified to to allow all the usual collection methods, then the accumulation will suddenly become a serious threat to one’s liberty and property.
Which is why I mean to evade the problem entirely by joining a Christian healthcare co-op, in which case I will A) avoid any involvement in the exchanges, B) avoid the tax/penalty, C) have some realistic means of handling extraordinary medical expenses, and D) avoid paying for immoral things such as abortion etc. Maybe it’s not for everybody, and maybe it won’t last forever, but for now, the co-op alternative is a safe haven that conservatives should at least be considering, especially if the aim is to starve the beast.