You seem to be misunderstanding how these devices work.

Bihormonal pumps do not mean continuous infusions of both insulin and glucagon. The pumps pulse insulin when you're high and glucagon when you're low. They're not both administered at the same time or continuously infused in a "balanced state".

The context in this thread:

> However, if your brakes (glucagon) can sometimes fail completely

A bihormonal system would not result in more insulin being administered than an insulin-only system for a given blood sugar, if the glucagon pump fails we would have an insulin-only system where we have plenty of safety data. There is no mechanism by which a bihormonal system has higher risk of hypoglycemia than existing closed loop insulin system.