Not signing for a package means nothing. You have a pack with 100g MDMA and you don't sign for it and think LE will just think "oh well maybe next time". No this is the USA and they are going to kick your fucking door down gunz-a-blazin. They're still going to get you, or try to. Not signing makes you look more suspicious. You get a free package in the mail who wouldn't sign for a free fucking package?!
For example those people that recently got 50lbs of weed shipped to their house. That wasn't their package but they still accepted and opened it. For all we know it could've been them that ordered in the first place they just had good OPSEC.
TLDR: Sign or no sign, you're gonna need a new door.
Whenever I'm expecting a CD, I simply switch two of the numbers on my house. So far, it's worked perfectly.