I'm having a problem with my new router with the top corners being rounded over, especially when doing parallel finishing passes. I've played around a bit with the z axis speeds and acceleration numbers but haven't had any real luck. I'd like to avoid turning off CV and going to exact stop because I do a lot of 3d finishing and my understanding is that is this would be less then ideal. Is there a way to turn CV off for the Z axis?

In some cad systems you can reduce the feed for Z moves or reduce the amount of overlap onto the top face or extend the Z height above the top face.

Basically, your acceleration is far too low for your current feed rate.  The tool cut path (white lines) is basically showing you what the CV calculation is doing.  The more accel you can configure your motors to have, the better the tool path will follow the programmed path.  I typically keep upping my acceleration until the drive faults or the motors start stalling/losing steps then I back off 10%.  Be careful, as the load on the tool will also affect the point at which the stepper motors stall.

If your system will not allow much more acceleration, then the ONLY thing left is to slow the feed rate to accommodate the slow accel settings.

Steve