One of the big-name-trainers has something along that concept (perhaps Clinton Anderson?). It is a pad with dimples, or recessed areas where the front of your saddle bars are. I think it is a good idea.
An even better idea would be if saddle tree manufactures would flare the ends of the bars of the saddle tree away from the horse a bit more. It wouldn't cure gross miss-fittings, but it would help a marginal fit not to dig into the horse's shoulders or loin area. I think the "Axis" saddle tree uses this concept.