Not testing is indeed your choice. Your reasons are your own business too, as many have said. However, you've posted on here to get reaction so I'm going to join in with that, if I may.
Porridge for breakfast is an odd choice. One of the first things I learnt when I was diagnosed is that most breakfast cereals are a disaster for T2s. The only type 2's I have heard of who can handle porridge at that hour, or indeed any time, are those who have been controlled for years. But hey, you might be one of the few that can handle porridge from the off. However, you tested at 9 m/mmol 45 mins after eating it. That would appear to show that it isn't the right food for you. It may have gone up more after that. Are you really happy with a food that gives you 9 m/mmol or more? I wouldn't be, not when it can be easily avoided by choosing other foods. Despite what you wrote in your first post, a spike of 9 is most definitely not "perfectly ok". Maybe the odd time at Christmas et but every morning? No.
Hba1c is useful in that it shows general control over a period of time but what it doesn't show are spikes. If you spike after a meal yet remain normal or low-ish most of the rest of the time, Hba1cs won't show this at all. You seem like someone who is very informed on the subject of diabetes, so you should know that if you're looking to prevent diabetic complications, the spikes are what we need to do our best to prevent. So you may get good or even excellent Hba1cs, yet still have regular spikes. Hba1cs aren't there to be 'passed' or 'failed', they're just a very general guide to overall control but don't tell you very much about what different foods do to your BGs. Besides, 'overall control' isn't really what we're after here, it's as few spikes as possible. No spikes would lead to a good hba1c but a good hba1c certainly doesn't mean no spikes.
I wish you the best of luck with everything, OP.