@John_S2 gave a great analogy. Except with Basal-IQ, the truck can’t slow down, it can only do hard stops, though sometimes only briefly. So you’ve got to follow that “truck” a lot more carefully, because it’s going to come to a complete stand still on the highway. His analogy better lines up with the Control-IQ algorithm, which can indeed slow down and tap the brakes.
Basal-IQ completely shuts off any basal when Dexcom predicts you’ll be less than 3.9 mmol in the next 30 minutes. This is a great thing, but also a bit of a weaknesses in the system if your BG is falling rapidly, just generally erratic (dehydrated, dying sensor, etc…), or you’re trying to intentionally lower BG pre-meal. It also resumes insulin the moment your BG changes direction, which may be too soon if you’re very low.
Basal-IQ was an incredible first generation product for preventing lows, but Control-IQ far surpasses it. Hopefully it gets cleared in Australia soon! Tandem has stated it should be available world-wide in early 2021. I’ve been nearly a year removed from Basal-IQ, so I’ve forgotten those weak points.
There are two different schools of thought on pump automation. Those who think it’s a tool to be used to maximum benefit and love to see it working, and those who think it’s a tool to be used to make settings adjustments and try to avoid pump intervention. I’m definitely in the former category. To me, that graph looks beautiful and like Control-IQ was behaving perfectly to avoid lows throughout the night, while still maintaining a flat graph near the lower range limit.
However, I’ve gotten the impression that you might be in the latter category and looking to avoid Basal-IQ having to kick in. That’s perfectly alright, too. If you want to avoid Basal-IQ kicking in, you need to reduce your basal, though probably only SLIGHTLY. The trade-off is that you’ll run a little higher at night, but you’ve got some range to spare.
I know you’ve gotten plenty of advice about adjusting correction factor (maybe even from me!), but we’ve all forgotten that correction factor doesn’t play a role at all with Basal-IQ… while being CRITICAL to Control-IQ. It’s completely irrelevant to you right now. The only adjustments you can make are basal rate and drinking lots of water to help your Dexcom data out.