To be honest I'm not sure of any additives or supplements that would boost your yield anymore than the products you have now. I mean, I could recommend some, but I doubt they'll give your plant anything it doesn't already have...sometimes it can be hard to keep it simple. Florakleen is a good product for flush, not needed, but is good. Until then, idk how compatible KoolBloom powder is with Maxibloom, but but it is good for the ripening stage and making the buds swell and produce an extra surge of trichomes...but I don't want to give bad advice lol...I just really can't think of anything else you need. To really boost your yield, you need to consider your lighting....what is your grow space, and lighting used?...UVB CFL bulbs are great to add during flower, because the plant responds to that spectrum by growing extra trichomes....
If you use a true full spectrum LED you already have UVB rays most likely.