i could be wrong in this, but im pretty sure the game has an internal metrinome constantly ticking every 3 seconds on its on, serverwide, reguardless of what you do.

what i mean in this is: it seems to be a known that DoTs tick every 3 seconds, however it isnt like WoW where you apply a DoT and it waits 3 seconds to tick (also resulting in it ticking the very last second the DoT's debuff is on the target). DoTs tick on their own
TP regen is also similar, sometimes you will get a tick instantly, sometimes it takes the full 3 seconds and everywhere in between
Mana regen seems to work the same way. I've had my first spell refunded the moment the mana was taken, ive had it wait.

If this is correct, there is no macro that could fix it. A program could possibly do it, but im not seeing it a good idea to rely on it.