But what you are talking about will not work for what the OP wants and does not work the way you believe it does. As Solon says, reset=15 will not make the macro reset after 15 seconds no matter what. It will make the macro lock up on an invalid spell {just like using Nill, or Null} until you STOP trying to trigger the macro in any way shape or form for 15 seconds.

You cannot ask the game to make if-then decisions, such as "If this spell is on cooldown, then make this button unclickable." You cannot ask the game to make decisions, such as "enable/disable this action every x seconds". They must be actions you make yourself and trigger manually, as Ualaa does with Keymap toggles.

If the OP wants to block a spell until the cooldown is up, then they should use commas for general timing or manual toggles.