Ah right, symlink would be a good workaround indeed, didn’t thought about that.
After a quick look it seems that the only way to make WP directly work with a custom htaccess filename would be to modify admin-functions.php.
The change looks really trivial but touching the main code will make it a bit a pain to sync with upcoming updates (even if it’s just a matter of a single sed oneliner 🙂
It could be a nice extra minor features to have it managed from wp-config or the admin interface I think.
Anyway, thanks for your reply!
a.