2 gal pots super soil?

would 2 gal pots half and half work with super soil most of the way thru? would I need to top dress around week 3 or 4 if so what with? has anyone tried this before?

Why only half & half? A properly amended soil mix should feed them through most of bloom phase. You could always top dress if needed but I suggest layering the bottom with a slow release fertilizer and/or use organic spikes. Cow or chicken manure is good for this as are Jobes a.p. organic spikes. For a top dress I would add some EWC, kelp, and fish bone meal.

What about super soil top dress or organicare pure bloom