Whilst Nathan knows a lot, majority of his writings are just based on internet research, so I take it scepticism and just the view of another.
Most of this practical knowledge is really just long range calibres and bullet experimentations with highly frangible heads.
the 7-08 can be loaded to 50,000 cup but 7x57 40,000 - that’s why the 7x57 is a handloaders cartridge. Factory ammo in 7x57 is weak at best to stay within the cup limits and accommodate for the manynold mauser actions out there, not the strongest large ring, but the ‘96 and small ring ‘98’s.
there is no doubt that if you handload safely, you can take the 7x57 with its larger case capacity to pressures around the 50,000 cup safely, and performance against the 7-08 will be superior without hesitation.
but as said, 7x57 is a handloaders. Cartridge, and if factory ammo is available locally in good choice and quality, and one does not wish to reload, then the 7-08 is a formidable alternative.