Can I use same wallets on multiple BC Vault devices?

You can use same crypto wallets on any number of BC Vault devices at the same time without any problem whatsoever. All the transactions are written on the blockchain itself and the BC Vault merely displays the data from it. What you are sharing between the devices is actual list of the wallets with their private keys.

To use same crypto wallets on multiple BC Vaults simply create a backup on the main BC Vault (containing all the wallets) and then use restore on the rest of the devices. All of them will function absolutely in sync after that.

Same global/wallet passwords and pins will apply to all devices (since backups are always encrypted with them).

You have to create new backup once you create new wallets and restore it on the rest of the devices.