And then one day one of your kids (or anybody who wasn't there in general) would say :
"Intelligent design requires another proof of the origin of a creator. Or a proof the design changed at some point. Or a visit by the guy."
And you wouldn't have the slightest shred of a chance of convincing them (by your standard).
Furthermore I would say that early cosmology theories pretty blatantly point to the idea that the design changed at some point. That very statement made me think of inflation, which does sort of look like it might be a deity saying "whoops, let's just quickly change this for a while". Or at least, that's about as good an explanation for what happened as any other we have (suddenly the speed of light changed by a couple dozen orders of magnitude for a few milliseconds up to a few seconds, and then slowed down again. Without that change, the universe would not have formed). It is also known that the laws of nature today are not identical to the ones in force 10 billion years ago. So there were massive changes in the laws of nature early on, then subtler changes later.
(Also a pet peeve of mine : please stop using the word "multiverse" or "universes" it's a contradiction in itself. The whole point of having a word like "universe" is that it's everything, and that means only one. If there were multiple "universe" there would still be only one. Given the size of the visible universe, the chances are pretty fucking huge that it is in fact bigger than we will ever know, assuming Einstein is right, and that of course also means that the big bang theory is a load of crock, even when "corrected" by inflation. We just don't have anything better (yet ?))
It is known that the universe is not zero-sum, and that this is normal (which means that there is in fact no natural law of conservation of energy+matter either. We already knew that conservation of matter was flawed, since nuclear power, and that conservation of energy is also not happening. Now, thanks to the LHC we know it's possible to violate conservation of matter + energy too). We currently do not know of any law of conservation that is valid "in the large", no matter how solid they appear to be on our little blue ball down here.