Planning a two week road-trip to PNW, Glacier NP, Yellowstone, and Grand Tetons at the end of July. Probably +6 years the last time I used my roof box and that was on my 11 MDX. So glad I test fit my 2012 Yakima Rocketbox Pro 14 on my 19 MDX because I couldn't find the keys I thought were in my junk drawer. REI sells Yakima cargo boxes and they had a huge key ring to test to find the right key for me to order from Yakima (only a few days to get 4 replacement keys for $26).
No problems with the Rocketbox hitting the open rear hatch. I've adjusted the Rocketbox forward as far as possible; but, it still slightly touches the roof fin antenna. I put a piece of clear rubber to help prevent rubbing issues on the antenna at hwy speeds. Planning to leave on for a week and make a few high speed runs to see how much vibration/bouncing I get at hwy speeds (I have more frontal overhand compared to when mounted on my 11 MDX with adjustable X-bars).
I still have my StowAway2 Max swing out hitch carrier if I get too much bouncing at +75 mph hwy speeds during my test runs. I don't like loosing my back-up camera, rear sonic/radar Acurawatch features in reverse, extra length needed for parking, and rear back-up lights at night with the hitch carrier.