My suggestion, don't be locked into the idea that you must use V3 clouds for everything simply because they are a newer option. It is not "wrong" to use each type where it is best.
V2 or V3 each has has its own strong points. Cirrus clouds for instance are still created as V2 by default.
IMO the V2 cloud type is better and simpler for dust clouds, so I would say use a V2 cloud for the dust and keep V3 sky clouds you already have.