Macros and skipping lines

[Niwashi]

/micon "Stone II"
/merror off
/ac "Stone III" <t>
/ac "Stone II" <t>

This kind of macro should do one of the Stone actions and skip the other. If Stone III is available, it will do that, but then you'll be busy with the Stone III when it gets to the Stone II line, so the Stone II won't happen. On the other hand, if Stone III is unavailable (either level sync or not enough MP), then it will skip Stone III and go to Stone II instead.

If it's skipping the Stone III even when you do have access to it, the most likely reason is you clicked it a little too soon (as though it had queuing like direct actions do) and you were still busy with your prior action when it hit the Stone III line, but had finished it by the time it got to the Stone II line. Just be sure your GCD is completely ready and not almost ready before you click the macro.