FYI, it's theoretically possible to write firmware that extracts the seed phrase from all current cold wallet models with a secure chip, BitBox02 included. The only difference between Bitbox02 and Ledger S Plus is open source vs closed source.

So after a lengthy research it seems that there's not a single "cold wallet" that can't be modified with a firmware upgrade to provide its seed phrase from its secure chip. This so called secure chip on whichever device is not some impenetrable fortress that is equipped with a isolated non-upgradeable firmware, such a thing doesn't exist. BitBox02 also tweeted and confirmed this, Ledger also did it.
And since it's all based on mutual trust, especially with Ledger, their only correct move would be to go completely open source.
3 years ago there was a reddit post about this and that all apps installed on ledger do have access to the seed phrase but noone realized the implications and the post never gained much attention, however the Ledger dev is discussing exactly this. Ledger's APPS have read access to private key? People buy ledger to trust the Hardware and not 3rd party APPS, how can this be OK? : ledgerwallet (reddit.com)

So, if you want something completely safe it would be best not to buy any products, just use an old isolated from everything PC/laptop and follow the tutorial with how to set it up with electrum wallet.