I have three which are accuracy and interferor response;
water content/moisture, blood hemocratic response and oxygen sensitivity.
The real tragedy, one has to try different meters or sneak around the FDA approval files looking for reports on these beasties!
Actually you make good point about care being casual. I got to 13.3 a1c; 330 lbs and started seeing eyes - hemorrhages - retina and kidneys going down; so decided the casual approach was going to kill me.
I had already cut out excess snacks, candies etc and did follow that - not enough! Now on Mediterranean diet, cutting carbs - grains back tightly and meter after my meals religiously and adjust eating. Numbers in line, weight down, kidneys stabilized and eyes/retinas clean last 4 years!
One reading a day/week is utter useless and the witch doctors proposing that should be shot!
I am deadly serious about it now - 1200 calories per day, 1.5 to 2 miles walking and metformin and insulin and read and learn all I can.
Metformin, insulin, diet and exercise key to managing mess.
The casual approach is after 30 years+ type2 in a word asinine and part of the reason this mess is so bad and numbers so great world wide!
It sneaks up quietly and what seems benign and then rushes the body in the end!