Yes, conical moulds are made for use in the ROA. However, my experience with the ROAs I have owned is that at pistol velocities a soft pure lead round ball is the more effective projectile. You lose powder charge capacity and a lot of velocity when you load conicals.
Yes conicals will fit. I done a bunch of testing with conicals in a ROA. Roundballs are way more accurate. Conicals also shoot a foot higher than the sights will compensate for.