I am also designing Max3D with older hardware somewhat in mind, but any such version - if it ever actually happens - will have *less* capabilities than Blitz3D. Which oddly enough increases the chance of a GL Blitz3D happening one day - unless Si H's MiniB3D gets there first!
Well if Bmax is slower on low end machine you could use blitzGL :) if it's append :) Blitz3d will have a reborn. :)