I don’t have experience with the aprilaire, but I also have a basement that requires a dehumidifier to run all the time. I’d love to try a whole home dehumidifier but wonder if you’d have to get the upper levels of the house too dry to keep the basement at the desired humidity (since it will always be more humid down there than the rest of the house).
One alternate solution I’d like to look into long term is a heat pump water heater, which has the benefit of being more efficient than more other water heaters, plus the benefit of dehumidifying the space around it due to the refrigeration cycle it uses. This only sounds reasonable b/c my water heater is on the older side so I might have to replace it eventually anyways. Wanted to throw that out there in case it was a possibility for yourself too! Not sure how it would work for the crawl space tho.
Full-disclosure: I’ve done VERY littler research on this. Just dabbling into some google searches in my free time and work in a related field and feel mildly knowledgeable on the subject.