Need to slightly alter SPropertyAssetEditor; do I need to replace it entirely?

Is there some way I can inject a different FOnShouldFilterActor delegate into the SPropertyEditorAsset widget (and make it use it)? I’m still learning the whole Slate system, but I honestly don’t see one.

Essentially, to give some flexibility to its actor filtering, it looks like I need to alter it’s InteractiveActorPicker to accept an FOnShouldFilterActor, and change it’s IsFilteredActor method. Both SPropertyEditorAsset::Construct (containing the former) and SPropertyEditorAsset::IsFilteredActor are private methods.

It seems a waste to rewrite the whole thing, and I don’t want to mod the source. Any thoughts?