Yes, that makes sense. Backwashing will dilute ALL pool chemicals so that means CH, TA, CYA, FC and salt. The only thing it doesn't change is the pH (depending on the pH of the fill water -- the fill water may have TA and CH in it as well). With an SWG, the only reason you might want the regular drain/refill that backwashing does for you is that hot and dry climates with lots of evaporation will cause a buildup of CH and TA from the fill water. Of course, one can always do that manually with a cartridge filter (not backwash, but partial drain/refill).
I have a cartridge filter and it's a 4-filter model for my 16,000 gallon pool and I've been very happy with it. My PB intentionally oversized it so that it wouldn't have to be cleaned so often and I'm so glad he did that. I only clean it once a year and I probably wouldn't even need to clean it that often. There's never a pressure rise and it doesn't look very dirty, even after a year. I have an opaque electric pool cover, however, so not much junk gets into the pool and I think that also helps a lot. When I want to intentionally dilute my pool water, I can feed the winter rains from the top of the pool cover (that has a small pump on it) and feed the hose into the main pool water to cause it to overflow and dilute.