Help needed: Xcode direct download & unpack

Hey folks,

I'm posting here for lack of better place, since I figure some of you might be familiar with this. I found the direct download link for Xcode 11.3 to download directly from the App Store servers without login in. I end up with a 7.8G .pkg file that I'm unable to unpack/install.

Using binwalk, I can see the file is not encrypted, but in a weird format. I can see there's signing information, too.

All the information is at https://gist.github.com/steeve/893b258e5a9ebd4b64cc2215ce73deac

Thanks!