Hi, can you add an option to make one way portals. For example players can go world to nether but not nether to world. I am running a skyblock server and player can go another islands with nether portals. Also they can have unlimited obsidian

you can set that visitors cant use nether portals on other islands and therefore stop the abuse of getting resources.

They are using on their own islands. When your island mate break the Nether Portal in your island and when you use Nether Portal in Nether World, a new portal is creating in the island.

I didn't realise this was in an other repostory. Sorry but I cant answer this here then.