Absolute minimum rotation speed
Are there scenarios where the start of rotation could intentionally occur at or below stall speed, say for extreme STOL operation (e.g., bush pilots)? I'm especially curious if it would be important for a STOL aircraft to have the elevator authority to lift the nosewheel off the runway at (or even a little below) stall speed during TO?
I'm aware of, say Part 25 requirements for rotation speed VR (not be less than V1, 105% Vmc, speed that allows reaching V2 before height of 35 ft after takeoff, or VLOF @ 110% Vmu @ max rotation rate) -- but perhaps there are much more aggressive procedures for other types of aircraft/operations.
Under ground effect, an aircraft's wing produces more lift at a given speed but stalls at a lower AOA (note this effect contributed to the fatal Gulfstream 650 flight test accident). I'm guessing these competing effects (more lift, lower stall AOA) close to the runway are a wash and the actual stall speed under ground effect is the same as airborne -- so one could not exploit ground effect for added speed safety margin while accelerating past rotation speed.