And there is another concern: the wiki doesn't create the line numbers using a separate table column in the generated HTML so any attempt to highlight the entire chunk of code and copy/paste it into another window grabs all of the line numbers, too. (Or at least, it did the last time I tried it quite a few months ago.)
So for longer examples that the reader might want to copy/paste into a macro window for testing/experimentation purposes, leaving out the line numbers is probably best. Instead, maybe some kind of font control or HTML comments can be used to highlight sections of code being discussed...? (I don't know how much font control is possible inside a <source> block, but I expect there isn't any.)
that is (still) true and indeed annoying. Though I still like it more with the line option on... no biggie though.