I like the idea just because for me the 11T cog is entirely useless. I mean, if my big chainring were 44T I might use it, but not if it's 50.

Right now my commuter bike has a 39-30 double with an 11-speed cassette on a 10-speed freehub that I made work by dropping the 11T gear. Even with this combination I could hit 30 mph by spinning a 110 cadence if I really felt the need to (but since it's a commuter I don't).