I do not see a way to shock the machine with this grinder at any point, therefore, I would have to say goodbye to ristrettos......
I don't think it's possible to have much control over this grinder for espresso. The half clicks are much too course. When I first got the grinder, It was difficult to hit consistent ristrettos, even with the locking pin removed. Things got easier after 50 shots, so I guess it takes time for the burrs to 'bed in'.
I'm a bit nervous about quoting click numbers, unless the grinders are sequential on a production line, but here goes. I'm pulling 1.4oz ristrettos (inc crema) in 40sec from a 15g load. My beans are very dark, I roast about 5sec into rolling 2nd for Haraar.. Fresh I would be between 9 and 9.5 clicks. As the beans age, I may go half a 'click' finer.
All I can suggest, is you increase your load by a few grams and see what happens. If you do decide to remove the pin, it's about 6 and a half turns, to remove the top carrier. Get an old toothbrush and the vac cleaner at the ready etc. When reassembling don't lube the threads, otherwise it may be difficult to counter the torque with one finger. Once you replace the top carrier, you will find it easier to use the screw above the square grind chute as a reference (see pic), so 9 (on the side) now becomes 2.5 on the front.