I see your point, Don - but - the raised rib on a shotgun, seems to me, was originally designed for the trap gun, which is mounted deliberately, then the bird called for.
When shooting fast, especially at moving targets, the rib really isn't seen or used at all - merely the front sight and with a rifle, the rear sight as well are used.

With proper fitting stocks and also properly made barrels, as Kamilaroi put forward, ribs, full length or 1/4 length, are not necessary.

When the rifle is snapped to the shoulder, all that should be visible is the bead nestled in the bottom of the wide V- superposed on the animal's kill area- exactly where your eyes were locked as you mounted the rifle.

I think it's best to have a 'proper fitting' rifle made up, rather than attach 'dodges and fixes' to repair problems in fitting.