The Garnet emulation appears to only have a square resolution, where the faux buttons take up the rest of the screen. Do you know if that is indeed the case or if there might be a way to let palm apps take up the entire Pre screen?
I've heard conjecture that Palm already had the rights from ACCESS to make a Centro simulator, rather than a full garnet emulator, and that they didn't want to go back and pay for the full garnet emulation, and that that is why it only runs apps in low res. Personally, I suspect that Palm might not have wanted old garnet apps to run in high res mode because then they would present more competition to new Pre apps and hurt app catalog revenue as well as the WebOS dev community.
Does Palmgoon's source know anything about the reason for the limited functionality? Personally, I'd find the Pre more compelling with better legacy support--that is, with high-res support.