I have also run into this issue and had to stress with clients that in some cases delays in permitting can end up costing as much or even more than just doing something right the first time. Most clients are very receptive to cost benefit arguments when presented from a professionally objective point of view. At the end of the day, the client did hire you for your expertise, and if there is a better way of doing something or better product to be used it should be considered part of your job to offer the pros and cons of the alternatives. Not that I think many professionals do but, to merely follow client instructions and stamp drawings with blinders on is a disservice to the profession.
