Good questions...
My recommendations to patients are not to plant the maximum they are allowed, but to try and rotate the harvest to give 1-1.5 x the amount of the anticipated need. In other words plan the harvest as best as possible. Under the law, there is no way to have a three months supply (as with an outdoor grow) fall under Section 4. It may be possible to justify it under section 8, but that requires a charge and a court case to prove the 3 prongs of section 8.
One issue that is a common thread in these discussions is 'I want to grow outdoors so therefore I will have more than 2.5 ounces'. The problem with this is that an outdoor grow is an option, not a requirement and there are other ways to do it that would get you closer to the legal limits outlined in section 4. Not to say you can't do it, or section 8 could not be viewed as allowing it, but you have to make your case and there will be hard questions from the prosecution to overcome as to why you made the choices you made.
To address your issue of it would be 'impossible' to stay in the limits, there are many that do. If you exceed them, there are a couple of problems. How much do you actually need? You don't get the 2.5 ounces presumed medical use with section 8, you have to justify every gram. Second what is your supporting evidence to use 'juicing' vs another method if you are trying to justify extra meds because you 'juice'.
Finally, I think one of the reasons they are getting a dispensary bill together, which hopefully will be law this session, is that they acknowledge overages go hand in hand with having 'enough' to meet medical needs. The extra income would be cool too for the caregivers with overages. The current law we have complicates overages and income, so correcting that by giving a legal outlet is a move in the right direction, it just isn't law YET.
This is why the act has a provision to be modified, one example is the widespread support in the legislature to modify the act to allow medibles. This is to prevent overreaching courts from reading things into the law, hence the current status of edibles.
Dr. Bob