how about for now, let's just have initram with its own copy of things, and then let the others link against stage 0 as usual.
I've done the 'vector table' approach a fair number of times. It eventually tends to run into trouble as more and more junk gets packed into it.
But, we can argue that out, and, for now, let's just have initram stand alone. We know we can get that to work.
ron