I have read through this post and I am getting a little confused as to what we are trying to achieve.
As far as I understand, CV is a system that comes into play when the motors cannot decelerate and accelerate quickly enough to achieve instantaneous speeds required, constantly. The computer therefore decelerates one axis as it accelerates the other so the speed of the tool is overall constant. I don't know if anybody has studied the resultant curve or not - is it circular, parabolic or what. I dont suppose it matters.
You can turn this effect on or off - and the off position should result in a sharp angle of cut.
A question - IF THE COMPUTER CAN ACHIEVE A SHARP CUT, WILL IT DO IT REGARDLESS OF WHETHER CV IS ON OR OFF
I understand that you are able to alter CV Distance and CV Feedrate. I can only assume that these two parameters only come into play if CV is ON - if it is off the computer will decelerate to 0 and then accelerate up again. I cannot see that you need both parameters - the computer will compute its dec/acceleration from either the distance it is told to start from, or the feedrate it is told to maintain round the shape - I cannot see how it can do both.
As far as the angle is concerned - Stirling - keep it simple.
Try a right angle and run with CV mode on.
I assume the feed rate must be pushed fairly high or the motor will be able to start and stop quickly enough - and up it until you are clearly getting a rounded corner.
I would try the Stop CV on angles, and try ENTERING from 88 to 92 - it may be that at 90 - if it is programed to stop when angle >90, it doesnt catch it - and see where the change from round to sharp occurs (if it does).
I cant see this diatribe will help much, but I cleared it up a bit in my mind, anyway.