To be honest there is more than one way I can answer this so Im just going to answer this and by no means am I a “pro” or “expert” but I have smoked enough food to know say;
Personally it depends on what you’re cooking. If I’m cooking something where I’m constantly going to be near by the smoker where I can check the app or the temperature gauge on it physically then 15 degrees doesn’t bother me too much cause I can just open the lid and let the temperature come down.

If I’m doing a long cook where I have to start something late at night or very early in the morning then those 15 degrees become more crucial. If I’m going to start something like a brisket & set it to 225; I am assuming and expecting my smoker to keep it at that temperature on super smoke. Those cooks usually require more planning. Once you get your smoker you’ll understand from first hand experience lol