You could easily go up to 10 speed in the rear as that's the same cassette width as a 9 speed, but when you go to 11 speeds you are going to have to make sure what ever wheel you are using has cassette clearance to the spokes. That will depend on the hub flange diameter.
I have a 2x11 setup on a 2009 Vertex RSL with 135mm dropouts and a DT 240S hub and it all just fits but the chain plates are very close at the inside of the dropout on the 11T and the cassette is very close to the spokes on the backside.
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