hello there Garofalo, I am going to try to answer some of your questions (if I would be able all of them) and I hope this is going to be at least somewhat helpful to you, but anyway.
so well, not specific to the adderall: the generics are very often quite less close of a match on the extended release formulations than they are on the instant release formulations and this is happening due to the fact that XR version it is much more difficult (much complex) to manufacture it and when they do try to do it - there might be errors and hence the lower quality. and besides this, I really think that the exact method of doing so often that it is remaining protected even when the drug itself isn't anymore produced, but this is only my opinion and nothing more than this.
regarding the pharmacies and what they have in their stocks… well, different pharmacies be sure that they definitely are carrying different generics in a lot of cases and in fact, sometimes even the exact same pharmacy is going to periodically switch which they are carrying when one of them is becoming cheaper than the other one. for them, obviously, it is a matter of profit and nothing more. in case there are some any other versions that are available through their distributor and they had simply decided on their own to order one over another one then they are able (and if they are willing ) to special order the version that you are preferring with an sufficient advance notice (which is obvious since, as I said, it is a matter of profit for them ONLY). yes I did found out which manufacturer a pharmacy has in their stock before filling and I've done that very simple: calling them. I have called pharmacies on some several occasions in the past in order to ask them if they are carrying or if they are able to get a specific manufacturer's version of a drug and I was also asking them at what price either. it is obvious that some of them might be quite less willing to answer such kind of a question because my questions were about controlled substance, obviously. I even found an pharmacy that told me this way: we're not giving such kind of information about controlled substances. that is why I suggest you to be careful on how you are phrasing your question. sometimes you might even need to ask all of this in person so they could see that you are not a junkie and that you have a prescription for that and you only want to know which one would be the best solution for you. try to search for your best one.
and yeah, one last note here… you need to be aware of the fact that Adderall it is a subject to government imposed quotas that is limiting production and therefore this is trickling down to distributors as well because this is limiting how much each of the pharmacy is able to receive in a certain timeframe and therefore this can result in some of the pharmacies periodically running out of something that they would otherwise have in their stock. this is something that happened to me on a several occasions and what the pharmacist told me. and also, I did have read those other posts where the people are describing that they are running around town to half a dozen pharmacies before they are finding one that are able to fill their CS prescription on the day that they do need it. so well, I would recommend you that in case your ""usual"" pharmacy is able to get what you need and you are going to have it reliable available each time at the time that you are going to need it then I would honestly recommend you to try to focus on building up or maintaining a good relationship with those working there and then, to do whatever it is taking to get to them during their working hours (since you said that they work up until 6 PM they you need to try to be there 5:30 PM). this is only my speculation on this but I do know that this very often helps. this really may help you in having at least some priority with them when a shortage might happen in case they do know when to expect you every single month for your monthly refill, rather than somebody else who is bouncing around to some other pharmacies a lot. somebody who they don't have any ideas who is he and whether or not he is going to come back the next month or not. there might be some other privileges that you would discover with time. my final point being that you might want to build this relationship as it may be helpful. good luck!