Good point!

But it does help the Plus's value that the ROM can now be messed around with in creative ways, giving it functionality it never had before (like booting from a ROM disk, for example).

That has been done on the SE/30 and most of the Mac II family by way of dougg3's custom ROM SIMM, and it's been absolutely invaluable in terms of all the extra funcionality it can add (which makes those models more desireable).

c