Ahha.
While true that the RED and some Epic and Scarlet models will take PL lenses directly, these lenses are very expensive to begin with, so the cost of an adaptor is the least of one's worries. A basic kit of 7 Panavision (Zeiss) PL primes is about $35,000, so the adaptor cost isn't much of an issue for anyone for whom this is of more than academic interest.
And as for the Canon, it can't even take a PL mount adaptor, so the point is moot.
Michael