the problem isn't the powder burn, per se. the 375 cart is blessed with a long neck, and this aids greatly in helping not only to burn up the powder plug before it reaches the throat of your bbl, but the cooler brass at the end of a long neck also helps dissipate heat much better, so as not to 'cook' the throat as well. such is the major bbl/ throat life diff in the 243 as opposed to the far superior life of a rifle in 6mm remmy.
So a chamber/throat in one 22 in bbl, will be getting equal punishment in a 28 inch bbl, the 375 cart does good work in trying to save the throat in either.
So you have to ask yourself, which do you prefer, are you humping this bad boy around, will you need to use fast manuever, will this be primarily used in a stand, can I handle the extra weight, do I want the huge fire blast and recoil of the short bbl, etc.