Downloading the blockchain isa resource-intensive process that requires a lot of bandwidth and time. Doing so over a public WiFi network increases the chances of the download getting interrupted, resulting in wasted time and bandwidth. and also could potentially violate the network's terms and service, which could lead to legal consequences.

It is very important to note that you should only discard your old wallet once you have you confirmed that ll of your funds have been successfully transferred to your new wallet. You should also make sure to securely erase any sensitive information that may be stored on your old wallet to prevent unauthorized access.

Make sure to store your passphrase in a secure location, such as a password manager or a physical safe, to prevent it from falling into the wrong hands.