You make a valid point Max - thanks for your inout.. although I guess ~99% of the time while I am on the bar and closed out I will not be tempted to offer the cube to my opponent.
Over the board, I would probably not offer the cube until there was at least one open point for me to come in on, unless there were fairly exceptional circumstances (i.e. am miles behind in the race, at say 5 away - 4 away and will probably lose the match anyway (say I have just ~4% MWC) with the cube already at, say 4, so why not bump it to 8 with that small 4% chance to win the entire match).
In five years of playing, I cannot recall being in a non-exceptional position where I have considered offering a cube while closed out and my opponent bearing off (which may say more about my poor gameplay than anything else). If there has been an open point for me to come in on, that is a different story.
Would be really interested to see any youtube links / sgf / transcriptions where somebody in a non-exceptional (or even exceptional) position offers the cube at a time when they have been completely closed out. Maybe when they have taken off all but the last 2 or 3 of their checkers? Or they are miles behind in the race throwing a 'Hail Mary'.
I can see how the non-autoroll makes sense in adhering to the rules of the game (choice of cubing) but I'm not sure how practical it is. In the real-life matches I've seen, most people just automatically hit the clock when closed out. Does anybody have any other common examples of closed out cubing?