With IS Boxer, you could use a Do Not Advance option.
Meaning, no matter how fast you spam your keys, the next step won't fire off until x.x seconds have passed.

However, you will still need to push a key when that time comes up.
Nothing will fire off on its own.

A lot of Death Knight teams use Mind Freeze, with a do not advance option.
Mind Freeze (talented) is off of the GCD, so can fire off whenever.
Step 1 (Press 1), sends to DK A.
Step 2 (Press 2), sends to DK B.
Step 3 (Press 3), sends to DK C.
Step 4 (Press 4), sends to DK D.
Because this is off of the GCD, you can imbed it into every other key that you'd press or spam.
By putting in a Do Not Advance for 2.5 seconds (in each of those steps), you have a Mind Freeze going off every 2.5 seconds (approximately) as the ability has a 10 second cooldown.
If you were to spam at one press per second, it would attempt to fire off 10 times over 10 seconds.
But the second step could not fire off on the 2nd press (1 second after the first) or the 3rd press (2 seconds after the first), but would fire off on the 4th press (3 seconds after the first push).
If you're like me, and spam your spam keys at 4-5 presses per second, it attempts to fire off every 0.20 to 0.25 seconds, and actually goes off almost perfectly.

But still, the ability cannot fire off unless you push the key when it does.
The software can ignore presses of keys, and can time when it will ignore an input.
But it will not give any output unless you give it an input at that time.