Eh, I find no reason to have big and/or heavy bags, and the plastic BBs have plenty of weight/density for proper support and don’t compact rock hard like sand or small lead shot can. Two small socks with plastic BBs can also be carried in a pack, with little added weight, for front/back field expedient stuff. For small, leather, true shooting rest topper bags, and small bat wings, sand is fine.....but for full bag setups, the BBs work better for me....of course, some places I have some true sandbags that stay there as a ‘base’ elevator, to get topped with a bean bag, but I’m not lugging sandbags to/from ranges, either.
There’s enough weight. This is what I’m referring to: