Something I've learned the hard way when I started at the moldmaking industry, back in the 2000s, is that we can't trust 100% on the 3D model our customers send us. ALWAYS check the 2D tolerances before everything else. If you have a dimension, let's say, 2mm, with a tolerance of +0,1 and -0,0, change the 3D product to 2,1. It will save you a lot of time after everything is done and the product doesn't shrink as expected.