The Heritage Foundation proposal did include an individual mandate, but that's like saying your bedroom ceiling is based on the Sistine Chapel because they both are covered in paint. The Heritage proposal was for minimal, catastrophic insurance, what used to be called "major medical." That's the sort of insurance people used to be able to buy for maybe $50/month. But the ACA larded everything up with countless mandates (birth control, etc.), so that even minimal insurance is now expensive. And then, in one of many ironies, deductibles are now so high that many people avoid going to the doctor. Remember when the ACA was needed to ban "junk insurance policies," which were defined as policies with high deductibles? Down the memory hole!
I said years ago, before this monstrosity came online, that it would not work as claimed, and in fact might never work. I believe that prediction still holds. They've stopped talking about the problems with the backend, but AFAIK they have not yet fixed them, and are still doing things manually or with estimates. It will also be interesting this tax season, when millions of people find that their tax bill is higher than they thought it would be, thanks to the ACA.