You must learn to say no to some requests from clients
If change requests from the client will make the design unsafe or unusable, you should refuse to change it. Otherwise you could still be sued as the designer for giving misleading information when your company is the expert (accepting a change could be deemed as approving it, even if you gave a warning that it would be unsafe or unusable).
Another instance to say no is if the client asks for changes that will increase the schedule but won’t approve the increased schedule. Get approval from the client for the extended schedule or cost before saying yes to the proposed change.
