I think it's a very poor treatment. Sure the raise is better defined when it's actually made, but your 1NTF sequences, which are overloaded to begin with, are even worse. Also, in the modern game the 1N bid gets overcalled far more often and the fit may get shut out. Plus, as lightly as many make limit raises these days, whats the actual range? 8 to a bad 9? That seems a terrible waste of a bread-and-butter sequence.