Awesome! I just found out a cool way to do insets :)

You have the original shape, and you do a project of the curve shape you want to be inset onto it.

Then you network it, and extrude it into a solid.

Then boolean subtract it out.

Easy :D

One thing I find about MoI - it has so many "hidden" features!
eg. Boolean Difference can also be used as a "slice" tool