A ST/STe version of this is definitely possible, even in 320x200. But it was not the purpose of this exercise - it would require a full teardown and rebuild from the ground up! The Falcon port was just a stepping stone for more complex things we plan to do. For example what we do even with bexagon is probably way too much for the poor ST to handle :).
Also, for those who like reading behind the scenes reports, here's a boring write up I made that documents the whole porting process: http://d-bug.mooo.com/beyondbrown/post/bello-basic/