I've seen them, but considered their use an unreasonable use of the design reserve/robustness of the Volvo drive mounting system. I suppose their rationale is that is only a few HP compared to the main propulsion, but I'm not sure that the plastic bushings in the yoke pins will be happy with the static load of the outboard itself. Most usable motors would increase the static load by 50% or more compared to the leg itself.
Also... where/how would it mount? The only way I can think is if it used some or all of the bolts that hold the top cover on. IMHO, not a good idea as these bolts and the threaded part of the drive that they torque to (into cast aluminum!!) are designed to keep the top cover on, not support the static weight of the bracket and motor as well resolve/absorb the thrust of the motor.
Just my personal opinion on an otherwise grumpy morning..
