England, currently dividing my time between university in Guildford and home just outside Reading
Too many to list here!
Having googled it, I assume you're talking about this? If so, I doubt it'll mess with the derailleur enough for you to notice. The actuation ratio (the ratio between the distance the cable moves and the distance the derailleur cage moves) may change ever so slightly, but not enough to be noticeable.
Specialized Sequoia Elite/Motobecane Fantom Cross Team Ti/'85 Trek 520
I agree! Smart idea. the only thing I might consider doing is somehow anchoring the bottom of the bracket so that there is very little deflection when shifting but the tension should be enough to mitigate any ghost shifting. I'm just picky.