Ooh. I'll have to try that out. Definitely sounds really good.
the katyusha creeping barrage has more or less the same accuracy at all ranges, unlike the default barrage. The rockets land in a lane pattern, so okw buildings in particular can eat up most of them without relying on RNG to kill them all (very close range katy should use default barrage tho)
Katy is very rng reliant (IMO) on killing support weapons on range, but this ability can efficiently hit them at longer ranges. The barrage travels quite slowly, they can see the barrage and possibly dodge, but you can always aim for the first rockets to land at the support weapons and kill in the first volley
a rarer application of the creeping barrage is to do....creeping barrage tactics, lol. Seeing axis infantry formations advancing via recon? cut one of their advancing paths by using the creeping barrage, though this isn't exactly a good tactic due to how unreliable it is