You may be able to get away with using the RDS sytem as long as your "rotating activator rod" is of sufficient torsional stiffness. Think of how much a 5/32" torsion rod landing gear on a trainer will flex for instance. On a typical .40 size trainer with 1/8" or 5/32" wire landing gear with a cross-fuse width of about 4" will easily deflect 15-20 degrees without too much force. I fear that using such a system on a larger aerobatic plane will lead to problems as the twist in the system will tend to "soften" the control response. The amount of twist in the RDS rod will be linear with the length of the rod, but will increase with the third power (cube) of velocity. Given enough speed, your surfaces may not deflect at all.

I am worried you will have flutter with the RDS system. If you use a carbon fiber torque tube setup instead of a simple wire you may be able to eliminate it. However remember you are building a plane with maybe 20% of the wing area (wing + aileron), nearly half of the total horizontal stab area (stab + elevator), and well over half of the vertical stab area (fin + rudder) is a movable surface. Sailplanes have control surfaces that are a significantly smaller portion of the total surface area, AND they only deflect a few degrees, while a Laser could experience up to 45+ degrees of travel (less for an IMAC setup of course).

I am contemplating building a 40% Laser myself, and will likely use the Durant system on the ailerons. For the rudder I will us a pull-pull cable system (which is scale, btw) and on the elevators I will use direct pushrods. It would be very easy to rig up a pull-pull system for the elevators as well, driven by an internal bellcrank attached to the elevator joiner.

Personally speaking I love to see innovation in our models. I greatly enjoy watching a single development system (such as Mr. Harley Michaelis' RDS control actuators) create a total paradigm shift in the state of our art. I would love to see it work in your case, but just realize that using a stock system may not be sufficient for your needs you will likely need to greatly upgrade the strength of the system.