Once you can do AQ4, then you should start doing it daily. With the changes to the drops, the guaranteed SSR drop should make it worthwhile... even though the average SSR is absolute garbage. You'll need the fodder.

As for when is AQ4 doable? Well, a full SR team with a full slvl20 SR Grid should be able to easily handle it. Considering how Energy Release system is out, probably much earlier than that. Try to read up the mechanics as they differ daily for waves 1 and 2, I think there's an old accessory thread for that buried somewhere. Started by sanathlig I think. Once you know the mechanics, just try it out now and then.