If you're running Sub's supersoil then you shouldn't need to worry about teas or top dressing or anything of the like, his mix is designed to last for a long time which is why there is so much of everything in there. I'm not running Sub's soil anymore, the mix I use is much more simple, Sub's mix should have all you need to go from start to finish.. even during an outdoor grow this holds true. In fact, I've run outdoor plants from start to finish in supersoil many times and only ever needed water. So unless you changed Sub's recipe somehow, I doubt it's a lack of nutrients.
If I had to guess, you may be suffering from nutrient lock out as opposed to a deficiency. Lock out and deficiency have the exact same symptoms, so it very well could be that. Look into the ph of your runoff if you haven't already.
Another thing to consider, when running organic soil, we're taking care of the life in the soil and not so much the plant itself. When I ran sub's supersoil, I used water from my hose. So pretty much tap water
Let me ask you this, have you ever let your pots get too dry? Especially in flower? If I had to guess, the problem is with the soil. But since you didn't have any problems before, that tells me that some of your microbes have probably died off and things aren't as efficient as they once were. Because if you don't keep your organic soil constantly moist, then it can have no life. And organic soil without life is just dirt. But don't trip, because a lot of these microbes just go dormant, and I'm sure there are still some there! All you gotta do is brew a simple EWC tea with a little molasses and oatmeal. Water your soil and be sure to keep things moist from now on. You should notice signs of improvement if my thinking is correct.