4 x .20 cal baffles and a .22cal stainless first baffle DPT on my .20Prac..... (They didn't make a .20cal s'less when I bought it). Just looked and there's no sign of cutting on any with just a couple of insignificant 'salt' crystals on the alloy baffles, I gave up taking it apart to check if there was any flame cutting yonks ago.
I bought an extra alloy baffle at the same time so if there was any flame-cutting or I needed it to be quieter, I already had one in stock so to speak.
I was using Viht N133 and was getting all sorts of problems with that.... struggled to get over the 'magic' 3600fps better BalCoef of .287 for the 39gn Sierra Blitz Kings, pressure signs on the primers, moisture in the barrel leading to verdigris on the next bullet and it chewed it's way through the stainless baffles on the previous mod. Hated it.
Then I switched to RL10X and life is suddenly a lot easier.... less pressure, and easily got to c3700fpsand, as above, no damage to the baffles.
Cheers
Fizz.