I agree.
You can use pistol type fast powders for light 308 plinking loads. But a suitable slow burning rifle powder for full power loads. N135/N140 etc. N135 may be a good compromise for 7.62x39 and 308win.
For 38S&W special and light load 357S&W mag, then powders in the unique/bullseye/N340 class are good.
Once you start using multiple powders, a very strong warning, to anyone reading this.... Only ever have one pot open on the bench at any time. When done loading, empty the powder measure completely back into that pot and put it away.
Getting powders mixed up, will at best be expensive. And that is only if you realise in time! A full load 308win with a wrong/mixed up powder, and you are going to get hurt.
If leaving powder in a measure (if you have multiple measures) put a piece of card inside with the powder name in big writing, against the side wall, so you don't get a mix up.
We recently had soneone mess that up on our range. Not all the gun was found, and some bits were pulled out of the range wall (metal sheeting) with pliers. Somehow only teh shooter on the next bench got hurt and not seriously.