How about a guestbook prop that you can craft and place where you want in your build and players interacting with it can leave short messages or just press a heart button to leave a like.
Messages and Likes would be stored in the beacon and guestbooks are just means to access it, so having multiple guestbooks access the same messages and likes and moving guestbooks would be no problem.
That would solve the “where to put the interaction” problem.
