The problem with using three-day CGM sensors for six days is that half of the prescribed batch expires before you get to use them. The benefit: I stab myself with that painful* insertion needle less often.
* The word “painful” is used for dramatic effect. It’s not comfortable, but it’s not really that painful. Really!
Sure, I could use them past their expiration date, but somehow they seem to be wildly inaccurate once that date hits; like the date is somehow coded in the sensor’s magical micro-electronics. (Maybe if I set the clock back on my pump). So, a couple of unused, expensive sensors are headed for the trash.