X2--Been using the Kit for years, have never once mixed it during the 30-day cook.
I've also been known to have a batch of soil sitting, ready-to-use, as when I mix I'll do two batches at a time, and grow in one. That way, at the end of the grow, I have a 3-month cooked soil that ss super active, happy, and ready to rock.
Of course, I'll top it off with water once or twice a month while it sits. So at the end of the grow, I can amend Batch 1, let it cook for 30 days, and start immediately with Batch 2 since it's been sitting, cooking, waiting.
Everyone has their own style, but honestly, it's hard to go wrong