Splitting stem

stem splitting hasnt been proven to do anything beneficial for the plant and in the case of autoflowering plant is likely detrimental to their growth and yield due to their fixed flowering timeline. in general with autos you want to keep the amount of stress you subject the plant to at a minimum to encourage vigorous growth. you especially don't want to stress the plant during flower because it cant recover as easily as a plant in veg. so I would personally just leave the plants free from stressful physical damage and instead just do some low stress training to boost yields and quality.

I think you are talking about stabbing the plant.I don't think it is a wise move.forget what everyone says on the internet,I would say.sad,angry,talentless,careless folks trying to find ways to abuse the plant. looking good,don't do any damage on the plant

Personally I don't think that topping typically increases yields for autos. If you're in week 8 though you should be well into flower and should not cut the stem in any way in my opinion. Sorry if I misunderstood what you were asking but anything beyond lite defoliation is too much during flower. Happy growing ✌️👊