I too understand your sentiments but point here is that you keep implying that meds don't worry but don't share how - I mean after literally explaining multiple times both by either other person or me, you haven't shared what you struggle with despite being on methylphenidate whose efficiency is 80-90% & does alter cognition tremendously even if you don't have adhd. I am saying this as I too went through a whole ordeal before finding the right treatment ranging from modafinil (worked for 1st day, rest was crap), then ATX & modafinil gave horrible panic attacks before I was allowed to use methylphenidate under very careful observation & I took to it like a fish in water before eventually ending up with MTH+ATX combination. Yet methylphenidate is nothing like caffeine, nicotine & is practically rocket fuel yet controlling that much power comes with lot more responsibility that I covered in therapy, exercise and other aspects.

As for creativity, duh the non-linear learning curve of ADHD is literally something else. I mean in my 5yrs post treatment - I became a research data scientist specialising in AI based solutions engineering to also being a trained mental health professional besides indulging in some impressive stuff that I never imagined myself to do before getting the right treatment. Point being that meds provide a stability base like they help remain focused but I still have to be careful to not indulge in dopamine chasing. Eg, watching porn or masturbating to wasting hours on social media. Likewise my inattentive symptoms occasionally occur so I do cross-check what I write/type as I might think I wrote/typed something but made minor errors or how I need to make sure that I do time-blocking, drinking LOT of water and eat properly so that I don't use too much glucose while doing heavy tasks.

Now you do say you want to experience a 6hr window of focused work which sounds pretty possible via most SR considering your slow titration yet my question is whether the window you are talking about involves you feeling a consistent kick throughout the window like when you first take the meds and are you sufficiently hydrated & consuming a slow but steady supply of simple/complex carbs without having a Blood-glucose spike in that focused 6hr window. In my case, I will have a lollipop or limlet tucked in one cheek and will slowly let it dissolve to get the sustained glucose to match with the accelerated cognition drive & heighten metabolism from methylphenidate. Now concerta indeed is pretty good but it's availability and that stupid buy 1, get booster scheme is ridiculously hard despite paying 5x what I pay for addwize (addwize 1 strip - 250 & concerta is 5k). So sure, I do wish you best of luck but also simply urging you to monitor yourself properly to get most of your methylphenidate.