For what it's worth, we removed davits from our swim platform, as they blocked the transom door from opening more than about 45 degrees, and took up a substantial amount of space on the swim platform. Having 3 kids, going to the beach often, the davits had to go. The motor was too heavy for the whole system, anyway, eliminating the convenience of crane style davits.
We have, for many seasons now, kept an inflatable (air floor, so it's light), tipped up on it's side, secured with 2 dock lines that connect through the cutouts in the platform. It's way easier to deploy the dinghy when we get somewhere, untie and push it off, as opposed to messing with the block and tackle setup that was there before! A short "dockline" stays attached to a side handle on the dinghy, which is what we use to tie it up wherever we're going, and also to pull it up while standing on the platform. Nothing is permanently attached to either boat anymore, nothing to get in the way of enjoying the swim platform, and deploying and retrieval, I feel, is way quicker than davits.
NOTE: We also have a Walker Bay that we bought for kids with the sail kit and the inflatable tubes. We kept that on the back of the 400 for two seasons in this exact same configuration. The Walker Bay was a bit heavier than our Mercury branded inflatable, so after putting the closer tube on the swim platform, I would go up top to pull the "retrieving line" from up there, and lash it so I could go down and put the lines on it. It was a bit more unwieldly, but it worked. Kids rarely sailed it at the beach, so we went back to the inflatable.
Also worth noting; the Walker Bay with 2 adults and 3 kids takes on water over the centerboard trunk opening. I've never had the plug in there to see if that increased capacity. We used it to get from the boat to the beach and back in the spring when the water was too chilly for swimming, so not a long ride. The inflatable has a much greater carrying capacity...