I can only see this going into a very dystopian path. Based on their actions, I don't trust these companies, their security practices, nor their privacy policies. Why would I give them my biometrics? And my full palm, at that!? Hell no!
Its hard to believe anyone would use the thing. It'll be more problematic if/when its used for regulatory purposes. Sort of at the desensitization still. Today.
I had to take a State exam for licensure a few years back. I was told that I had to take a palm/vein scan to prove my identity. I informed her Ive never had one so it could not prove my identity-- but hey, Im the crazy one. Its on a server somewhere now tho... Modernity is pretty stupid, tbh.
The thing it these readers are so convenient, my only complain is I wish they would work as the password hash technology. But as of right now we don't know for sure if that machine is saving a "hash" of your palm or is directly saving a copy of the original biometric data that would allow it to "recreate" your biometric ID somewhere else
I just don't subscribe to the slippery slope arguments I am provided when it comes to privacy. I and I suspect most other people just prefer convenience to some hypothetical threat to what I am not sure.