I've never tried splitting logs for posts, I've seem many a mile of fences that were split hedge posts.
They started in on the biggest knot with their wedges, working towards the small end of the log. Once it was split to the small end they worked the other direction, from the knot, to the big end. I dont know if they worked them green or 'cured'. But dry hedge does seem to split easier by hand for me, not sure about BL since it doesnt seem to get very big here before it dies.
Harry, I guess either method would work, just that the finished product might look somewhat different. I did run onto some BL the other day in some bottom land that are 40+ feet and about 12"-14" diameter that all grew up together nice and straight. The thought came to mind how this would be easy pickings for you but decided to clean up around them, maybe cull a few. Letting the best of the bunch grow a bit for barn timbers.