You can order what you please, 60g being the max. But if you consistently order less they may reduce your allowance at next interview I guess.
Which I would always contest because it only took me a few months on medical cannabis to realise that, actually, it's
necessary that your allowances exceeds your actual requirements because being able to grab an extra 10 g or so in any given month to build up a small surplus to cover eventualities like late deliveries, bank holidays, delivery issues, the clinic cancelling consultations until after scripts are due, is vital, because all of those things will happen at one point or another.
If the goal is to treat the patient's actual symptoms as consistently as possible as and when they appear, and not to conduct the pointless mathematical exercise of trying to match the prescription size to the
average monthly requirement and completely ignore the fact that some months will exceed that average and some gaps between deliveries may exceed one month.
My actual needs are probably somewhere between 30 g and 40 g, and my wallet finds 30 g highly attractive compared to my actual allowance which is 50 g. But in 3 out of the 5 months that my allowance was 30g and 40g I suffered some issue that was no fault of mine but the fault of the clinic/delivery that left me without medication for up to about 10 days during the worst delay. Since my allowance has been 50 g there has been no gaps and I've got a small surplus that means I shouldn't find myself with gaps for a good while. It was more expensive than I'd have liked to get to that point, but I'd like to think I can drop down to regularly purchasing between 30 g/40 g in a couple of months time and not have them punish me for that by dropping the allowance.
In addition it's not necessarily always about the number of grams but the number of strains. For example I medicate for anxiety and depression, sometimes what's best for my depression and what's best for my anxiety aren't always the same. Sometimes my anxiety manifests as daytime rumination, in which case I need something that calms me but keeps my focused and alert, other times it manifests as nighttime rumination and troubled sleep, in which case I need something that calms me and is a lot more sedative, sometimes my depression manifests a difficult time getting out of bed and starting my day, in which case I need something very energising and which sweeps away the brain fog. That's three different strains I need, and the chances that I need an even 10 g split of all 3 is slim, so although I might not necessarily need 50 g of actual flower most months, I do need access to at least 40 g so I've got enough of the 3 different flowers I'm looking for.
Now, if 5 g pots became the standard, and clinics had a demonstrated track record of German-style service efficiency, then we can start to decouple number of strains required, number of grams required and surplus level required, and then I probably would be open to reducing my allowance to 30 g or 40 g. But that is not the world we live in currently.
Plus, if they put my allowance down to 30 g, the additional range anxiety that I'm going to run out of meds would probably increase my medical needs lol, thus qualifying me for 50 g again hahaha.