Sorry for the delay.

Well, let's say you have an undercut with 3,5mm as this picture shows. Here I calculated a movement of 6mm to avoid any problem with the extraction. This calculation is easily made measuring the X distance from the vertex of the slide hole to the end of the cam pin. In this case, 6mm... If you need a higher opening value, you can increase the cam pin, always measuring this 2 points, adjusting everything else to your needs. I hope it is clear to you. Surely there are other methods to calculate, but i personally think this is the easier one.

Here it goes. Please see the attached file. Feel free to ask if you have any doubt. Best regards