One other piece of software I use does automatic renumbering of custom Islands..

It is so flustering when I get the message on here, that there are 2 custom islands with the same number... sometimes it just is a pain...

Pretty please?

I would not know how to even address this issue.
Since you can order the islands as 1,2,3,4 or 4,3,2,1 or 1,3,2,4.
So if they are auto numbered how can you decide what is first,last and in the middle?

the other one renumbers everything by 10

10
20
30
etc

When you have a lot of them, it gets to be a pain to find which one is double numbered

Or even if they could be sorted by number that would work as well

I guess I get your madness.
It is confusing to re-sort the islands.
Maybe not a auto number is needed but a display that allows you to drag and drop the islands around with a graphical display, to get away from the numbering order completely.
I think that was where version 8 was headed.

Or a little pop up box that says that it is sharing a number before you hit submit. I know the pain on that one takes forever to find which ones are the same