Shoutout to the $22 flat rate box that killed my zone chart headaches

I ran an online store selling handmade candles out of my garage in Boise, and for two years I priced shipping by weight and zone like everyone says to do. Every order meant weighing the box, typing the zip into the carrier site, and guessing at the padded envelope size, which ate 10 minutes per label and I still ate refunds when I guessed low. In March I switched to flat rate boxes for anything under 3 pounds, and now I grab the same box every time, stuff it, and print the label without touching a scale. My average label cost went from $9.40 to $7.85 and my packaging time dropped to about 2 minutes per order. The catch is bulky stuff like my 4 candle gift sets, which I still ship by weight because flat rate punishes anything that does not pack tight. Has anyone else split their shipping between flat rate and weight based, or did you just pick one and stick with it?