One of the failsafes is the conservative amounts of insulin the software is allowed to dose on its own. In my case, it is set to never deliver more than 1.2 uni

One of the failsafes is the conservative amounts of insulin the software is allowed to dose on its own. In my case, it is set to never deliver more than 1.2 units of insulin per hour. If it wants to deliver that amount, it will instruct the pump to raise the continous supply of insulin for half an hour. In contrast, I will routinely instruct the pump to deliver 8 units at once for a meal. So if say the blood glucose sensor delivers faulty measurements (that happens frequently in my case) it may gradually try to kill me, but it takes hours to get me into a dangerous zone. This is a lot of time for me to notice and correct. I mainly like the system for correcting while I sleep. I wake up less to a low sugar thanks to the software suspending insulin delivery, and high sugar at night is often corrected by the time I wake up. I don't know about failsafes on the lower levels. I kind of trust it after a year on OpenAps :-)