any handler that doesnt have a sane no-target possibility should foward to the appropriate documentation page
That's a reasonable thing to do, but to my mind a better approach would be to let [foo://] DWIM from the writer's POV. IOW, if I want to link to the Perl Changes Browser, I write [apc://] If I want to link to the Wiki Wiki Web, I write [c2://]. If I want to link to the Perl docs, I write [doc://]. If I want to link to Wikipedia, I write [wp://]. And so on. Rather than assuming the author made an error.
There's precedent for both approaches ([id://] vs. [apc://]). However, given that [id://] doesn't have any other useful default semantics, I'm not convinced that this is the precedent to follow. I'd rather follow the [apc://] precedent.
We're building the house of the future together.