It could also be useful for other types of link: git commit, bug reports on github, etc. But it's harder because there is no simple way to know what the reference is about (e.g. "#4242" for a github ticket or PR: for which project? LuCI, package feed?)
http link will automatically be shown as e.g. [[flyspray>2637]]
Nice!
EDIT: One caveat though:
If you link to a flyspray issue which you have found via the search function, the automatically created interwiki link may come out unwieldy wide, like so:
I asked the creators of the interwiki links plugin if they could modify the plugin so it automatically creates links like [[flyspray>3033|FS#3033]] (without manually adding |#FS...).
Seems to be not that easy, requiring several hours of work for a rate of friendly 110,-€ per hour. Wow.
If we had someone knowledgeable in php in the forum, maybe we could do it ourselves for far less than that.
-> You could create a new 16x16 icon for FS, place it in the correct location, and it will be shown like e.g. the wikipedia icon when using [[wp>....]].
This will still show only "3033" as text, but the icon should give a hint what's behind.