Yes, there is a macro that does this. No you can't have it because it was nerfed out of the game way, way back.
[edit] also, yes, there is lag when switching targets. This is a fact of life when multiboxing. FTL does it. Focus setups do it. Everything does it. Give yourself some time after a target switch depending on how much latency you have before expecting your alts to see the target change on your main.
Basically, the reason for target switching lag goes like this:
- Leader changes targets.
- Leader's WoW.exe client sends notification to the server that you switched targets. (+250ms)
- Server confirms notification of target switch and notifies everyone else your leader switched targets.
- Alt clients receive the leader's target switch and can accurately target the new target.(+250ms)
Substitute the +250ms with whatever your normal lag to the wow server is, and add about 250ms for client and server-side processing to happen. So, the example above is about what I'm running here on wifi (230ish pings) and it takes my alts about 3/4 of a second to see the target change and actually swap to the correct targets, depending on other factors like prime-time server lag.
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