Can I drive a Compound Wall height with the "Top" option through a GenerativeComponents node?
Yes, you can generate a standard Compound Wall via the Wall node. In order to drive the height value first create a Compound Wall part definition that has variable height defined along with a corresponding DataGroup Catalog Item. When placing the new Compound Wall using the GenerativeComponents Wall node you should be able to link a slider to the Wall Height property and adjust the height using that slider. "Top" in this case is set to "FixedHeight".
Note that if using the Top > Plane option instead, the wall graphics may not display correctly if the plane selected results in "minimal" graphics.