Feature Request: Add 2 safety features for maxCOB and maxIOB #1863

Is your feature request related to a problem? Please describe.

1. There have been several instances where a bad CGM reading (or reading in the future) has caused Loop to deliver maxBolus (or 40% of that value) at 5 minute interval, leading to excessive insulin delivery.
2. There have been several instances where user accidentally entered a meal more than once which has caused Loop to deliver excessive insulin.

Describe the solution you'd like
Add a user adjustable fail-safe value to Loop.

One idea:

maxIOB:

• Automatic Delivery of insulin checks current IOB and if the recommended automatic bolus would exceed maxIOB, limit automatic bolus to not exceed maxIOB and issue a notification to user.
  • Manual Delivery would not be limited by maxIOB (or perhaps there could be 2 settings, one for automatic and one for manual)

maxCOB:

• When accepting a Carb entry or edit, check to see if the COB with that carb entry would exceed the user selected maxCOB and refuse to accept the entry
  • If user wants to proceed with the Carb entry, they could modify setting or loop might offer an accept button for one-time use without modifying maxCOB selection.