I know MoI is very precise, but when you are drawing you always have to type the measure by hand. I always have think of a feature that let you set a precision for all what you are drawing with a fast toggle. For example i can set steps of 0.1 and then it will not let me draw something with more 0.000's in it, just multiples of 0.1. With the grid snap you can get a little bit of that, but if you want an angled line it stop working. Maybe this can work for limiting angles too.

This can be a really time saver.

The UI is almost there, maybe just replacing the "snap size" option in the "grid snap" pup up for the "precision" option.

Just an idea.