For those of you who used the upper deck of your pack n play for your babe to sleep in.. Did you transition your son or daughter to the lower area as soon they hit 15Lbs? If not, when?

My son isn’t due for his next checkup until 2/22 and I know his weight is getting close to the recommended limit, buuut our scale at home + our method of subtracting his weight while we hold him is probably a tad skewed. 😆 Any suggestions or feedback would be appreciated! 🙃