My experience with belted cartridges goes back to 1969 when I bought my first one, a Husqvarna in 358 Norma Mag. Man, I was riding tall in the saddle then! IIRC, the next one was her roomate, a 308 Norma Mag.
Then came a cornucopia of many belted cartridges: 270 Wby, 7 mags, 300 Wins, 300 Wby, 323 Hollis, 338 Wins, 340Wby, at lest six more 358 Normas, a 350 Ackley Magnum, 375 H&Hs,one 375 Wby, 375 & 416 Taylors, a 458 Win, and a few wildcats on the 300 Win Mag case.
Somewhere along the line, I had a Mark V 240 Wby for a while. It wouldn't do any more than my 240 Page SP or my 6mm Ackley, so traded it for a 22 foot freighter canoe.
Even had a 460 Wby that I never fired. Bought it from a guy who fired it twice!

Bevan King got it from me a built a 416 Rigby on it.
Through all of this, I never found a problem with a belt. Just load them properly, adjusting the sizing die to headspace on the shoulder, and cases last as long as any others. One thing I did discover for certain, was that W-W SuperX 300 Win Mag brass is about as tough as they come. That's what we used for the 35-300 and 375-300 wildcats.
Ted