[sirinsidiator]

You can! All you need to do is call UnregisterForUpdate for the name the callLater is registered with. It will return an id when you call it, so you can unregister it like this:

local function ClearCallLater(id)
    EVENT_MANAGER:UnregisterForUpdate("CallLaterFunction"..id)
end
 
function foo.EnterCombat()
  foo.myHandle = zo_callLater(function() d("you take too long") end, 5000)
end
     
function foo.LeaveCombat()
  ClearCallLater(foo.myHandle)
end