I got further info. You cannot take off from land and then land in water or vice-versa. If you install the retracts, you can disable them and put the nosewheel cover on the hull. It can be sealed with clear tape. You now have a dual-purpose airplane, but it can be flown in only one role or the other: water or land, not both on the same flight. Conversion from one or the other only takes a few minutes. The airplane does fufill the dual-purpose role as advertised.

I likely misunderstood the R&D tech I spoke to when I got the answer I posted earlier.