sending the mnemonic seed split into several parts via different encrypted channels is much easier than sending the actual device. I've used something similar to receive mnemonic seeds for my Fork claiming service.
Sending the seed would rather be a better option than sending the actual hardware wallet, but both of you knowing the passphrase and seed is not a good way to transact, you are also correct that the hardware wallet is already compromised, as it is written, you should only use a hardware wallet that you are the first to set up.
I have one and it was also delivered late, I think, for a month. And I just found out it was in our local post office, I just don't get why they didn't send a notification. Though, I'm glad it is still well packed and sealed.