Any question answered...

Ladies and gents, I'm thinking of buying a decent handlebar bag e.g. the carradice carradura (relatively cheap)

My question is, how bad would it be for my gear cables structurally and shifting functionally if I mount a handlebar bag like this:

Has anyone had experience of riding like this for extended periods of time?

fitting V-brake noodles to guide the cable out of the shifters might help. Googling reveals this isn't a new idea, but doesn't throw up much specific information.