Yes. That’s correct. That is your Developer Team ID.
Still making no progress with this.
I have looked into the plist properties and notice that there are 2 entries viz:
LSIItemContentTypes and UTTTypeIdentifier, both of which contain the bundleID together with a pointer to a file type for saving preferences (ie -pfPrefs). I updated both to both to be consistent with BundleID but on building the app, the resulting plist in the built app reverts them to their previous value, i.e. not the values shown within the plist editor.
I sent a private message to you. It would be good to know your Mac setup (macOS version, Xcode version, etc).
Still… being the “.pkg” using the bundle id as the file name… seems really odd to me.