Is the boot loader that XPF installs just a means of making it boot with extensions from both the DVD and the hard drive when you first boot Tiger to install it, or is it required for other things too? (ie would you need a modified loader even if you made a DVD with all the necessary extensions on it?)

Do any of the XPF extensions provide OldWorld support or had they just forgotten to remove it from Tiger? (how much does this matter, as I thought the Mac OS ROM is more of a Classic thing anyway, OS X doesn't really use the ROM?)

Thanks for the input so far everyone!