It can be worth it to be consistent, even for short periods of time, as it can help you "benchmark" your settings and get things dialed in more precisely. I "winged it" for a long time, just using insulin like something I'd buy in the parking lot of a Grateful Dead concert, 10 units here, 5 units there, roll away the dew, etc. When I got the pump and started checking out the Medtronic "pie chart" reports, I could see "well, the roughest time of the day, is the morning, how can I fix that and I'd see that my metabolism seemed to slow down a lot in the evening. I'd be, like you say, 110 ish and seemingly cool at bedtime but run up so I'd see the 110 and stay up late, test again and see that it was going up, the late night snack lingering, the insulin slowing down or whatever.
Then the pump, it's like day 1 is super zippy, day 2 is ok but the results seem to lack some juice the days after. Maybe sort of eat the bigger foods on the first days can help smooth things out. Food stuff here at Tu can end up being pretty low carb. I might be bit lower but am not by any meants uber low. But, on day 5 of the pump like today, I'm cutting back for the most part.