Well in Dragon Rising that didn't work because the savepoints are placed so that you will take the direct way. It basically worked like that flank and the game won't save or take the path the developers intended you to take and the game saves and be less effective.
btw didn't you lose all your savepoints if you too the hud/crosshair off difficulty? I thought that was a bit poor.
Even vietcong gave you one save on vietnam mode iirc. - was there a way round this on DR?