So for shadestep, the full macro should be:
↓ Ctrl
↑ Ctrl
⌚ 0.1 sec delay
↓ Ctrl
↑ Ctrl
That will press and release CTRL, wait 0.1 seconds, then press and release CTRL. It sounds like your macro presses on CTRL, holds X seconds, and then releases it. I'm not sure if 0.1 seconds is the right amount of time for a doubletap, but you can test it.