hau Steven, indeed goat weed, Aegopodium podagraria is a rhizome reproducer and that does make it tough to get rid of.
Some things to do for building a compost heap in an area this stuff is present in;
Do put down a cover between the soil and the composting materials, old, discarded carpet works very well for this and you can use more than one layer if you need to.
Make sure the heap gets hot, the hotter the better, this is easiest done with green materials in the center of a lot of browns. (browns are
carbon, greens are nitrogen)
If you have or can get spent
coffee grounds, they are a good source of nitrogen.
Keep close watch on the moisture content of the heap, monitor the internal temperature, turn the heap once the internal temp starts to go below 140 f.
The option would be to dig the space where you want to build a compost heap first to remove as much of the
root and the rhizomes as possible first.
In this case, don't worry, you will be providing new bacteria and fungi via the compost heap to the soil you disturbed.
Redhawk