Comment 12 for bug 664526

The options aren't available in the installer menu where you can select language and keyboard because that's too late; these are kernel options, and the kernel has already started by then.

I'm slightly bemused by this bug, though, because this is already how the installer is supposed to behave, and has been for many years; any boot parameters after the "--" separator are supposed to be copied into the installed system. If that's gone wrong then it is definitely not by intent.