Short answer: with the L-brackets one notch lower on both sides than usual, the effect of the WDH was barely better than not using the WDH at all.
Long answer: I had to lower my L-brackets because I lost the bar used to snap the trunnion bars onto the L-brackets. I could get the driver side bar on the L-bracket myself, but I couldn't get the passenger side trunnion bar even close to the L-bracket. We were leaving on a weekend trip, so I had to get the trailer hooked up; as a result I opted to lower the L-brackets just so I could lift the trunnion bar onto the L-brackets (both sides). I figured that being attached would be better than nothing. Turns out, that's true, but barely. I felt the trailer tugging and swaying as we went over road undulation. The feeling was more like towing without the WDH than it was towing with the WDH.
With a new trunnion bar snap tool in hand, I won't have to deal with the lower position on the brackets again.
Until I lose the tool again, that is.