This is a good point actually and I'm not sure I thought about this before but this could actually be another legitimate explanation for the different effects we get depending on how we vape and what device we use.
Like if we start with a gentle extraction then we will be decarbing the bud to a slightly higher ratio than we are extracting from it first is a higher initial temperature and more rapid immediate extraction where the ratio of decarbing will be much lower and perhaps not as complete (?), but certainly over a lot faster.
And likewise as you start off a load and you are building the hits when you get to hit 3 or 4 and the Vapour is dense and it really smacked you in the face may be part of that potency is related to the more gradual initial inhalations decarbing the bod and preparing for a monster hit.
Just a dumb stoned thought I am sure but that's what came to me just now. Maybe there is a little something do it to explain or contribute to the phenomena of highly variable effects between vaporizer model and many other factors.
Edit- to address the topic here- my gut feelings are that is just an entirely unnecessary consideration ynys St to decarb your weed before you vaporizer this is the amazing thing about vaporizing cannabis you automatically get pretty much maximum efficacy from the cannabinoids and actives which are delivered into your system in a readily bioavailable and psychoactive form automatically by the process of being heated and converted into vapor.
At least that is how I thought what it was and I believe it is. This is why vaporizing cannabis is such a popular trend because it just works you can't really go wrong once you are set up.
I often think it is a shame in fact that it takes so much work and an efficient process to make cannabis as medicinally effective, potent and supportive with non vaporized methods.
I mean we infuse our own cannabis coconut oil but no way am I convinced that the same degree of endocannabinoid and general health support for the body is delivered as it is is with vaporizing the same material.
Decarbing weed before vaping= madness and just unecessary IMO.