I want to get dehumidification as well. Dennis spec'd my ERV's. I like them, but they make humidity worse. There is some dehumidification that happens on the incoming air as part of the exchange, but the ERV isn't 100% efficient so there is still a noticable net gain in humidity brought in. I have to run the AC and ERV at the same time to deal with the humidity. The problem in the basement is its naturally cold down there, so the AC almost never kicks on. The ERV runs on a cycle - it can't be tied in with the main HVAC (the 2 don't talk). So it's bringing in fresh, but warm & humid air into a naturally cold space where the AC hardly ever runs. I think there is potential for a condensation problem. So I've stopped using it unless I'm down there generating a heat load and can run the AC without freezing. I think a dehumidifier after the ERV would be beneficial, but not sure how well they will work together in series.
I had originally thought about doing an external mixing room. Put a minisplit in there, ventilation, filtering, deodor, dehumidification, etc. Then duct that in through a powered dead vent. I'm kind of wishing I had gone that route, although hard to say what problems that might have created.