The mc-Things team has already done a good job improving Wi-Fi and MQTT support by lengthening possible usernames and passwords, and adding ClientIDs.
Another idea is to have a priority list of known network names and passwords, very similar to how macOS manages preferred networks. Imagine being able to prepare for a network change in advance by having a few passwords to try on the mc-Gateway. Or, what if a mc-Gateway is mobile and jumps around different networks?