Sorry for the long post….
Metformin unlike most other diabetes drugs can not reduce the blood suger level to a unsafe level, as it increase insulin sensitivity, so your body will still be able to automatically reduce how much insulin it is making if your blood sugar level gets too low.
This does not stop you filling unwell due to not having any thing to eat for some time (like most people), just that you will not go into a comer due to it. Our bodies need to get used to living with a lower blood sugar level and will try to trick us into thinking we need to increase it when we don’t. (A good reason for a meter so we know when we don’t need more carbs.) Also just the stress of being told you have T2 could result in you "felt dreadful at work, and messed up a simple subtraction".
Metformin over the long term can reduce blood sugar level a lot, but it has little short term effect, hence a lot of people claim it does not work if test their blood sugar every day. It does work very well and most people soon get used to it and any issues with GI stops for them. (A few people keep having GI issues and they post a lot to forums etc.)
I think everyone with T2 who is willing to be active and learn what to eat etc should have a meter so they can experiment with different meals and see the effect. Getting feed back in 2hr rather than 3 months is a very good motivator of change. But a meter is not needed to be safe with T2 if you are just taking Metformin.
NICE has found that most people who are give meters are not active and don’t change what they eat based on the readings, therefore giving out free meters have not been found to be cost effective. But anyone reading this post is not “most people”, and are very likely to benefit from having a meter.
Personally I think providing meters on the NHS for all T2 is a waste of money unless “controlled curb” eating training, along with support groups etc are also provided. Someone just writing a reading down each day and changing nothing about their life is of no benefit.
I expect that giving out copies of DVDs of “doctor in the house” showing shows when there is someone with T2 along with copies of “Living Low Carb” would be money well spent.
Remember a meter allow you to do scientific experiments on yourself to help you learn what works for you, but it is only of benefit if you will engage with the results and act on them.