If you want to prevent IWT from killing you (pulling more adds or just running off the ledge in Grim Batol), try this.

Keep your DPS key on step 1.
Put the IWT keystroke on step 2.

Under advanced for that keypress, have the button reset to step 1 after 0.5 seconds.

This way if you need the IWT you can spam click but if you don't need the bugged movement, you click or scroll once a second. That way he should arrive right on the target instead of past the target.

The more I mess with step macros the more I like them. I do the same for movement keys now too. Such as 1 press = main, 2 press = range, 3 press = melee. You get used to it pretty quickly. Gotta have the reset condition in there though and on a reasonable window.