It would be great to have a parameter to ignore existing LocalSettings.php.
In my case, a wiki_farm, I run many wikis on the same MW codebase, and I have a script to create new wiki instances. While trying to retrofit my script to use install.php, I found that there's no way to make it ignore the existing LocalSettings.php file, which is effectively a dispatcher to instance-specific configuration files.
I expected that specifying --conf to a location where no LocalSettings.php file existed, would do the trick, but it seems that this option is ignored.