As was partially brought up by William, shouldn't we consider using
bech32? It doesn't break on double-click and it is a dependency for
native Segwit addresses anyway, so wallets might already support it or
they will at some point. But we should probably run some numbers on this
first, since bech32 will obviously be larger than base64.

Bech32 is a BCH where the error detecting properties are optimised for 1023 chars max and in the special case of the Bech32 BCH, error detection of 4 chars are guaranteed with a max length of 90 chars.