If you used edge control (especially using Petrus for the F2L) to make sure the edges were solved with the F2L, that would leave you with 42 configurations (plus mirrors and inverses) to solve the corners. Would that be a reasonable option for solving the last layer using one look? I think the recognition could be a lot better than using ZBLL. Also, if you wanted to generate algorithms for the last slot of the F2L, the recognition wouldn't be too hard, would it?
I'm sure at least some people would agree that if you wanted to do a 1LLL, then it would make sense to either use a 1 look/2 algorithm system, or to influence the last layer to decrease the number of cases, and decrease recognition time.