In the US according to my real-estate agent from 10 years ago it is common to take out a loan for the 20% down-payment so you don't get the long term penalties.

This seemed to completely miss the point of a down-payment, but apparently banks were willing to go with it. They even offered the dual loans as a single product for convenience.

If you work the numbers out it can theoretically save money over the long term vs. renting long enough to save the 20%, especially if it means you can put more money into risky stocks with high returns, but it also increases your risk of financial disaster if the bubble for some reason ever stops inflating, but that never happens as we all know.

Personally I though it was too sketchy and went for a more traditional loan, but I know several people who took loans like that.