If something transcends our ability to be understood through naturalism alone, does that mean we have no means to understand it at all?
Yes! 'Cause there is no objective scale to distingish one argument from another. For example, any statement of your intelligent designer's motives is equally plausible. Hell, there isn't even an objective scale which can measure how many intelligent designers (bunnies, unicorns) might exist; that you believe in one god instead of many is simply an arbirtrary matter of happenstance.
Don't you see, man: the conditions which need to exist for belief in your god to be reasonable would require us to believe in an infinite number of things which may or may not transcend our ability to know them.