As per discussion in the Bluemap discord, it would be nice if ChunkyBorder could redirect nether portal generation in the same way the vanilla worldborder does.

What currently happens with nether portals in Chunky?

E.g. if nether and overworld both have a radius of 4k blocks, what happens if I build a portal in the Nether at the border?
Without ChunkyBorder, the portal in the overworld should generate very far from where the border finishes. Unsure what CB does when the overworld border is too small

Currently the destination portal remains true to vanilla, but the player is teleported into the border when they enter the portal. I don't imagine it's too consequential for most people, but my interpretation here is that some people may want chunky to reproduce the vanilla world border behavior, so that it isn't necessary to set the vanilla one on top of the chunky one for this feature.

One issue is that the vanilla world border behavior is only defined for square world borders, whereas chunky supports multiple different shapes, so replicating this behavior will likely not be exact. Though this is probably the best reason for having it, since it isn't feasible to overlay the vanilla border over chunky's if it isn't square.

Last few months have been busy for me, but I'm hoping to have some time for this (among other issues across various projects) soon, so if you're interested please feel free to give your opinions or suggestions.

Thank you very much for the reply pop - understood.

I'll contribute wherever I can, and I've subscribed to this thread. I wish I could help with a PR, though I don't want to produce a pile of spaghetti since I have no clue how to use the Bukkit API for this purpose.

Give me a ping whenever you like 👍🏻

This doesn't appear to be possible via the API right now so I will unfortunately be closing as "wontfix". 😦

If it becomes feasible in the future I'll definitely take a look at this again though.