What's the longest lens i can hang off an e-mount, on a tripod?

One of the things that really appeals to me about the Nex is the ability to use manual lenses with the focus peaking function.

For some reason, i really like using teles up to about 135mm on crop sensors.  I have 2 manual lenses in my pentax gear, the 100mm f2.8 measures 2 1/2" long, the 135 f2.8 measures 3 1/2" long - metal/glass construction.

The new Nex 6 is 10% thicker than the 5n or r, so if the base needed to be more stout, perhaps the 6 is the way to go.

So my question is: what length of lenses will the Nex cameras support on a tripod?  I know weight is a factor as well, but length has a lot to do with torque on the base.  Am i needlessly worrying about this?

Thanks for any comments,

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Phil B Pentax K5