Edit: or just add a way to get back from /island visit
If you visit someone to get back to your island you need to use /island home. But if you visit your "neighbour" you can't use it as you'll get the message "You must be at least 1000 blocks from your island to use the command". So to use it you need to go farther away from your island without knowing where it is

This is an interesting question. . . I was considering getting rid of the /island home feature in the pack I'm currently working on but leaving on the /visit for multiplayer servers . . . I wonder if you could use the inventory option from the waypoints mod to get home?

Also, I've never used the "/island visit" command and I'm wondering if this would leave you stuck in spectator mode when you got back to your island, or to the spawn point? If so hacking things this way might cause more problems than it solves.