Some benefits of standard supervision are lost with flexible supervision. The main risk is due to the fact that there is no validation performed when associating an Account to a Plan. The purpose of hardcoding Product Version IDs in Supervisor Contracts is to allow several checks to take place in order to assert that a Smart Contract and a Supervisor Contract are compatible before they go live; this is not possible with flexible supervision.

One of these checks asserts that the event types overridden in the Supervisor Contract do in fact exist in the supervisee Smart Contract; in flexible mode, an event is overridden solely on the name. If the names:

Match, then the event is overridden

Do not match, then the event is not overridden