I can confirm that this is doable without a macro and 0 delay.grf.
There were 2 servers that this was possible and i played on both for a little bit. I know the clients didnt have 0 delay grf, cause when i tried that it wouldnt let me launch the game.
I didnt use a macro and was able to do it when being hit.
I think the servers used Hercules, but i dont think the rAthena vs Hercules would matter in this case