The Genie Intellicode screw drive door opener barely fits to the ceiling in my attached garage because the ceiling is so low. I just adjusted the track mount at the header as high as I could to keep the top edge of the door contacting/bending the track. Whoever 1st installed it didn't care and either had notched the top panel door flange to clear or it just wore through it after so many years. The door now barely clears contact to the screw drive track, but it works much better and is getting quieter as I get more tacky red grease into the screw track. To get the door to clear the track, the track is now not level, but higher at the header versus at the power unit. But it has the power to easily push the door from fully open to closed.
I still plan to convert it to a jackshaft style opener. Pretty certain I can mount the power head in a way to access all the adjustments, and mounted so down is still down, up is still up. I'll still use the Genie microswitches mounted to the ceiling and door header to set the travel limits. I'll add an L-shaped arm onto the door top panel rib to contact the travel limit switches. I have an idea to make the sprocket on the power unit shaft free-wheel, but engaged with a notched "collar" (like the shifting dogs in a motorcycle transmission) to transmit power to the torsion bar tube. If the door needs to be disengaged from the power unit, just pull the release to cause the notched collar to disengage the free-wheel sprocket and the door stops, just like it does now with the release lever on the track shuttle.
The power unit load sensors and eye-beam sensors will still be used just like stock. The jackshaft conversion will eliminate the track, screw, shuttle, potential for track noise and greasing, but still maintain the safety switches and sensors. I'll mount lights on the garage ceiling, wired back to the power head so the lights come on when the door opener is powered just like it is now. I'll gain some overhead clearance in the attached garage, it'll be much quieter.