@Jen, for the past 4 months we have experienced the same thing as you. It clearly sounds difficult to believe to those who don’t experience it—yet it is exactly as you describe. Some of these changes, for us, are sports-related and we understand why they occur: we can even predict them reasonably well. But others are not, and we have no idea why/how yet. For instance, we had several days last week at 0.75U/hr, following 24 hours later by several days at 1.1U/hr, with reasonably flat nights after IOB is gone, clearly indicating that, at least at that time, the basal is reasonably set.
We have essentially dealt with it the same way as you. If we have to deal with a sustained high that stays stubbornly up after bolusing more that 4-5 times, then we set a temp basal. The same is true when dealing with a stubborn sustained low (several hours) IF we cannot explain the low with IOB. When it becomes clear that we have to take sugar every 30-60 minutes or bolus injections every 60-120 minutes without an end in sight, we set a new temp basal.
If we keep the temp basal for 48 hours or more, then we set up a permanent basal profile.
It is extraordinarily frustrating. I have described some of our problems here: Three months pumping and really frustrated
As much as changing basals sometimes almost daily is a difficult thing to do, the alternative, which is taking carbs every hour or more, or insulin every 90 minutes, does not make sense.