I think the key here are 3 things:
1 - Set hierarchy param to true (supported by the plugin)
2 - Set post type supports page-attributes (supported by the plugin)
3 - Set rewrite to true (not supported)
So I think I need to work on the 3) issue. In the meantime, can you just try 1) and 2) and see if it works?
Hi @skynet, I've just tested steps 1) and 2) and after refresh permalink, it works. Can you try refreshing permalink (just go to Settings > Reading and click Save changes)?