I like the thought process, the only problem with incentives is that a veteran like Carr will probably want LTBE incentives, which will complicate our ability to fit him under the cap. Better to just give him a few more bucks in a signing bonus to keep more space.
A few more bucks will cause a riot on this board. People forget Kirk cousins has consistently been one of the highest paid QBs even though he's a mid-tier guy that always flops in big games.