Would you know if the Templars charged interest? On the other hand, I believe I've read somewhere The Koran forbids charging interest. But perhaps I am mistaken?
Essentially, the Roman Catholic Church turned a blind eye to the Templars usury, largely because of the value provided by the Templars in enabling an endless stream of warriors for Christendom. They did set some arbitrary limits on the amounts that were permissible, but didn't have much in the way of methods of auditing or enforcement.
Note that the article does not discuss loans, per se (although, the Templars also got involved in that). It is more an international money transfer and currency exchange service. No doubt, the Templars charged hefty fees for their services, but they did not class any of it as interest as usury was definitely considered a sin for Christians at the time (as it still is in Islam).
Essentially, the Roman Catholic Church turned a blind eye to the Templars usury, largely because of the value provided by the Templars in enabling an endless stream of warriors for Christendom. They did set some arbitrary limits on the amounts that were permissible, but didn't have much in the way of methods of auditing or enforcement.