Susanne,
Unfortunately in Okinawa, out reefs are very delicate and crawling with urchins, so walking on live hard corals with fins is a no go. I understand that if you had a nice sand beach entry then puting on your fins on land and walking out would be ok. We may have to walk several hundred meters/yards with water waist to chest deep, because the surf breaks out farther on the edge of the reef. The reef gets often gets shallow again near the break. This is where felt sole booties to prevent urchin puncturing the bootie and spring straps are a must. It is very quick to slip the foot into the foot pocket and transition from walking and wading to swiming or the opposite on exit. To help in the transition I have my fins straped to my BCD, this way I can maintain my balance as I am climbing over rocks and holes and trying not to step on sea slugs. It only takes seconds to put on my fins from on clicking them off my BCD, to getting under the pounding surf. It is dangerous to be side ways to the wave when putting on your fins as the wave will smash you against the sharp coral. The reverse/exit is also true. Often we surf in on air holding onto the bottom while the surg passes over us. We will surf in to about 1 foot of water, and it is perimount in between sets to quickly take off your fins and stand up. If you don't the surf will roll you and pound your head into the coral. Once you are standing up the breaks around your knees don't knock you over but you may have a 100 meters until you can climb a hill to your car again climbing over lava rocks and hard corals. I can not see any one doing this in any fin. The felt bottom booties are not only a must for the urchins, coral, and lava but also for the super slick algee that grows on the dead coral.
Susanne, I know most divers don't dive to the extreme like we do here in Okinawa, Japan. Maybe your R&D can design some fins for us and I will test them for you.
PS I read Smart Questions Make Smart Divers again and it sounds very scientific, but I don't see any real world results.
For instance I conducted a Discover Scuba class today and was leading around a 250lb+ man who had a 5mm wet suit and about 25lbs of weight. He was completely dead weight. I easily took him on a tour, manuvering him for 30 minutes, while I finned continously for 2 dives each. I did not get any cramps, and I did not get fatigued. We moved together about the same speed as new divers do, stopping only to look at the sites. For manuverability I give my splits a 3 out of 5 (can not do helicopter turns) but for speed and power I give my splits a 5 out of 5.