I think you have three options, full height to allow dry box/cooler to go under, 6' or so just for a lockable oar storage type compartment, or flat bed. I need to measure the heights on my rapid rig since the questions keep coming up
Mine is not lockable though.
Yes, flatbed is easier and faster but really you are talking the difference between 1 minute and 3 minutes to load it higher up. Winching it up does not take long enough IMO to make a meaningful difference, it's just easier to float right onto a flatbed. Storage needed would be a more important consideration to me. If i was a fishing guide going out everyday then maybe it would matter to me.
you kind of have the hybrid utility trailer deals like this too.