First I would make sure the main focuser knob on the sct is turning counter clockwise during the focus curve - so it is pushing up against gravity.
Second - the entire focus curve appears to take about 1000 steps. Each person's step size could be totally different from another's - but the curve itself normally requires just a small turn of the main focuser knob. So if you only have 500 steps of backlash, it isn't removing much backlash at all. I would aim for 1/4 to 1/2 turn of the focuser knob to remove backlash - which for your system may be about 2000 steps.
A lot of this stuff you tell by 'feel' if you remove the autofocus control and just turn the knob clockwise and ccw. With the scope aimed up you can turn it clockwise for a bit - and then start turning it ccw. You will feel it take some time to fully engage - and that gives an idea for how much backlash you should remove.
Frank