You cannot mirror your keystrokes using software (ISboxer hotkeynet for example) or hardware (kvm synchronization switches for example) to multiple wow clients at the same time or in order to automate or to streamline the multiboxing process. You can alt tab that’s fine and you can have wow windows open, manually navigate and control them one at a time that’s fine too. You cannot have software or hardware playing one or more accounts for you in any capacity, including keyboard bound multibuttoned macros. So if you have 3 wows in window mode and manually switch between them, manually put them on follow, and manually cast spells, that’s ok to do.
Least from my understanding. I’m not a GM or MVP, but this is my understanding of the ruleset.