So this will be a bit more about the starting point of the question - more than about caffeine - to clarify a few things.
The 'How to be a portal' videos had such title with the intent of explaining what it takes to walk process and so eventually get to be that point of physical equality and oneness. But! It wasn't intended to be taken literal as in 'Do all of these steps and you will be a portal' as such as what Sunette is and does. Nope.
The title back then was perhaps intended to be a curiosity point that would lead people to consider walking process, and ultimately realizing that it's not about 'being a portal' per se, but about getting into the process of self-honesty. So, no, nothing and no one is implying that you will in fact 'get out of your body and experience the interdimensions' if you do everything that is said in these videos. It's been explained several times how there's only one portal - oneness and equality means, there's really no 'other' portal needed, just one, and whatever has been required to walk this process has been published and continues to be opened up as needed for our process on Earth.
So, with all of this what I mean is look at the starting point of why you are doing anything related to process, is it about the idea of 'being able to leave your body and go into the dimensions?' and what would that be for? Perhaps this is something you have to look at because, not any other person that I'm aware of walking the Desteni process is doing and walking process because of the idea of 'leaving their body,' because! We understand that what matters is HERE as Ourselves PHYSICALLY. Even Sunette as the portal is and has to walk her own personal process just like anyone else does, because this is where the actual 'birthing of life' as oneself, one's body, one's mind, one's being really is.
Therefore a more supportive look at your question is not really about 'quitting something SO that I can 'leave my body' but rather asking yourself why would you be expecting that? what kind of beliefs or ideas are you building around the idea of 'portalling' or something like that? are you wanting to get away from the experience of you, your body, your life? Are you creating ideas of the 'afterlife' being a lot 'easier' than life on Earth?
I won't go into discussing the answers to these questions, they are also explained in various ways in Eqafe, including the series The Portal and I
that Sunette made, which I recommend listening to in order to clarify your starting point in relation to walking process which means the whole assisting and supporting yourself to become the best version of yourself right here on Earth where we are all in actual need of doing that for the betterment of life in general.
How I would approach it is if I see that quitting drugs or any other harmful habits for my body is actually making me feel better, be more aware, be more stable in my body, then, why not focusing on that being the goal of it?
Caffeine is a stimulant and like anything, if you over do it, has consequences. I've stopped it for pregnancy reasons, but even before that I diminished it since I realized it was creating a buzz I had not experienced before as uncomfortable... who knows what I will do later on, but as with anything, it's not to 'demonize' the substances, it's about checking our relationship to it. If coffee 'gives you' certain good feelings etc, then that's something you can look at, which can create a dependency to it to 'fee'l certain way, instead of looking at how you could instead get to practice Living those expression through other ways or activities that you can direct yourself to get to do in your life.
Sorry if it sounds too commanding and repetitive, but, I suggest to not take anything as a dogma. Learn to discern what's best and what's not for yourself as well, otherwise we create a 'following' of something and remove that sense of self-responsibility. If you decide to quit drugs or get healthier, do it for YOU, not even for 'oneness and equality' or portalling or whatever else may come up as a reason. This is all about SELF being the starting point. That's my take - take care
A suggested public chat to read on: https://forum.desteni.org/viewtopic.php?f=152&t=8807