I had considered this way back (DSL days). However, the listmodes of Xvesa is reporting from the graphics card. The monitor is not necessarily able to display such a max mode. In fact, I rarely see such capability. Perhaps it might be useful on matched systems (monitor + graphics card), e.g., laptops, but even netbooks typically need 915resolution. I would need more convincing that such a boot option would be useful.
Would it really work on many systems?