Except that eBay and C&S tracking is to the verified address and standard satchels are to the delivery centre/postcode. As there is no verified address.

And eBay satchels are cheaper, and C&S satchels are marginally(?) cheaper than standard ones. so why would you use them.

You are fully cognisant of this, as you use eBay labelling (by your own admission), so I would suggest you are obfuscating, for reasons known only to yourself.