For those maneuvers I think that pilots are better of adding in elevator themselves than counting on a radio mix to "cheat" the maneuver. Especially for rolls. If you want to do a very slow roll you'll need to add in elevator manually so that you can react to what the plane is doing. Some times the plane will need more elevator when inverted, and other times it will need less. You should be reacting to what the plane is doing in the air instead of counting on the radio. Many factors such as wind, fuel load, or even a slightly different throttle setting can make planes react differently each time through a roll.

Ken