Board Game Arena

Way back in the day, I played Catan on a website called jsettlers and learned about NTRR (no trade, reverse robber). It felt to me a far superior way to play the game, and I was excited to see the friendly robber varient as I thought it was going to be full reverse robber for the whole game. Other robber varients I've played and prefer to the original are progressive robber, where the robber must first be moved to 2, then 3, then 4, and so on. Any chance these variants could be added?