Very nice!!
some IPM treatments you can still do during the first 2 to 3 weeks after flip, depending on how harsh the treatment is. it's really only once the pistils come in that you have to worry to spray something that'll stunt the flower production.
I've seen something as mild as a full dose of Neem completely toast all my pistils, buds stopped forming for about a month, when the plant finally flowered she made a bunch of poo weed.
though, you could still spray Neem till you see pistils which will only be around week 3. if it's something like a contact killer like Pyrol rather stay clear from day one of flip.
on the other hand, biological stuff like AQSF you can spray at any time. it's just distilled water with living organisms in it. you could also introduce predatory mites at any time. I see a lot of people working with predatory mites these days.