I believe that need for the belly flop isn't due to weight but is needed for the higher reentry speeds the upper stage. The current F9 reentry speeds are nothin

I believe that need for the belly flop isn't due to weight but is needed for the higher reentry speeds the upper stage. The current F9 reentry speeds are nothing like what is needed for orbital speeds not to mention from Moon/Mars. If you are already doing a belly flop for reentry, you might as well do it all the way down to minimize the landing fuel penalty. For unmanned flights you can do it really late even if they crash at a low rate. I would expect manned flights to be less aggressive, especially near term.