Interesting thread, for sure.
If the Pro needs a 30" bbl. to burn all that powder and perform as designed, maybe Nosler nailed it with the 26.
The 26 Nos case capacity may be about as much as one would want for a 26" barrel in a hunting size/hunting weight 6.5mm rifle for general use.
The Pro appears to be a very specialized set up for ultra LR shooting and maybe not ideal for general hunting use.
Just a thought.
DF