It sounds like you're trying hard to justify ejecting brass on others at the range when there is no justification and no excuse. Somebody using three benches doesn't excuse it. Someone having expensive equipment doesn't justify it. Someone taking up a bench for 60 minutes adjusting their gear doesn't give the green light. Nothing GG said or did in his post or at the range excuse it. As has been mentioned, you're responsible for your ejected brass.
You're telling us if we all agree to conduct ourselves as you believe proper at the range, then we won't create any problems for you (or range users who agree with you); problems that you (or range users who agree with you) could point to as a justification to eject your empties on others at the range.
And you're inferring that when the semi-autos start to unload their brass on others, that we're obliged to leave our bench to make room for them. How about them being responsible, or patient, or whatever it takes to understand that they're responsible for their weapon and damages or injuries they cause with it, such that they ensure their use of the range doesn't physically affect other range users.
I don't see this much different than what happened to a guy I knew that while fishing, hooked an adjacent fisherman in the scalp. The hooked fisherman got identification from the guy that hooked him, went to the hospital to have the hook removed, called his lawyer and pressed for financial compensation. The fellow who hooked the adjacent fisherman in the head... his insurance company agreed that he was liable and compensated the fisherman that got hooked. It didn't matter if the guy he hooked was standing 2 feet away or 15 feet away. He was responsible for his hook ending up in the other guy's scalp. No excuses. No justifications. It required a cash payment to compensate for the hospital bills, pain & suffering, lost opportunities during a vacation, and whatever else the attorney dreamed up. You can throw out excuses until you turn blue in the face. Your brass hits someone in the eye, you'll most likely be found responsible by a judge or jury of your "peers" in this country. And your opinions to the contrary won't mean a thing. The only opinions that will matter are a judges, or the majority of a jury (in spite of buzzgun's feelings about majority opinions, they do matter.) So if you're gonna carry an attitude to the range, at least make sure your homeowner's insurance is paid up.