Flat by itself isnt bad but off plane is. The over rolling with the left side will have the butt end of EdZ's flashlights pointing outside the plane after the club switches ends on the backswing. If your Hitting read Single Wrist Action, you dont need to roll .
If you still think your plane angle is too flat then Im guessing that you are missing the UP that EdZ alludes to, in your Right Forearm Takeaway. Which makes me wonder if you are Fanning and Bending or just sort of "sawing" an in-line deal with the Right Arm. A Push Basic type takeaway which is for short shots only. See Punch Elbow and learn to "Fan and Bend" as described in Alignment Golf 1.
I often have to remind a student in early days to "pick the Flying Wedge up rather than drag it around and up'. The flashlights will show you fast if you are maintaining or throwing the plane away. Beware those hips turning too quickly in the backswing as that too allows a flatter off plane motion.
Ask why it is turning flat and you can fix the route causes. Awareness is king of mechanics and fee.