Which is how legal insider trading for management works these days. Because
cancelling a 10b5-1 is perfectly legal at any time.
So you could totally abuse the system by submitting 5 of them, designed to allow for different strategies, then cancelling some of them to pick specific trading strategies based on more recent insider info.
And this works: cancelling them is normal, so that won't even attract much attention. It's a matter of executing well on this loophole.