This is more difficult than it might seem because it will affect a number of features - water, entrances, roads etc. But why do you need this? What would such copses represent?
i hadn't thought about that, makes total sense!
the notion i had was that the inverted version would represent the woodlots maintained by e.g. farming communities for timber or by nobles for hunting grounds, these being relatively small and surrounded by pasture and farmland , compared to the current version showing clearings surrounded by indefinite woodland
also, just want to say i think it's amazing how responsive you are to comments on all these generators, really appreciate it ! the generators themselves have been absolute godsends for my campaigns as well
You can try to achieve something similar in the Village Generator, just hide buildings (Layers > Buildings in the context menu) if you don't need the village itself. Cheers!