I've seen a few people attempt this, but with mixed results. The biggest issue is that it adds complexity to the trailer, and therefore the chance that something will fail. Any particular reason why you want to have it down? Is it throwing the center of gravity off?
I've actually thought of the possibility of raising mine in a similar arrangement, but I always come back to the same thought: "why mess with a good thing?"
Tell us more about the uses you give the trailer and the idea behind making it adjustable?
Editor, South & Central America
'99 UZJ100 Toyota Land Cruiser