⭐ Merited by JayJuanGee (1)
and btw what's up with manufacturers naming hardware wallets with boring number 3, first it was Keystone, than Trezor, who is next Bitbox or Passport? 
Based on the information I found, Keystone used to have the Keystone Essential and the Keystone Pro. But the latter is just a better version of the former, so it's basically Keystone 1. Their Keystone 3 and Keystone 3 Pro versions should then be Keystone 2. Again we are looking at almost the same type of device. So I don't follow the logic of naming it Keystone 3. It would make more sense to call it Keystone 2 or Keystone 3 and 4. It makes more sense for Trezor to do it. Trezor One is #1, Trezor T is #2, and Trezor Safe 3 is #3.
Important thing he notices about open source claims, Keystone said they will enable it later in November, that is next month so let's see what happens.
They call the wallet open-source software and hardware-wise all over their website and shop. Making it open-source in November doesn't change the fact that it wasn't like that in the past, and if the code wasn't verifiable, it could have done anything during that timeframe.