If I was a member of a club talking about a system like this, I wouldn't be helping them research it. I'd tell them to take a hike and join a different club. Seriously.
If people at your range can't keep rounds on the berm, the solution is to KICK THEM OUT, not cater to them. If you can't keep rounds on the berm there's a 99% chance you're doing lots of other things that are very dangerous/stupid.
"Accidents" happen, some due to negligence and a lot due to people who are relatively new shooters or new to the type of gun. The one time my PD decided to roll out a machine gun for us to get "familiar" with at a local gun club, rounds were going over the berm, that is a fact! There are houses alongside the club and a few on top of the berm to the right, none were there when the club was built in the 1930s, but from the 1950s onward lots of houses were built in what was previously nothing but woods.
Braintree R&P took the heat for rounds hitting a building 660yds downrange from the pistol range. NRA range experts, etc. determined that it really wasn't possible from the range, but the outdoor ranges were shutdown for >1 year while baffles were installed, berm raised and a requirement for ROs being present were all implemented.
Every report after one of our NES shoots includes claims of people shooting the ground in front of the target, shots going high (or over) the berm, etc. And those are all the "expert" shooters here on NES!!
And if my auntie had testicles she'd be my uncle.
OCSA has an elementary school and sports fields about 15 degrees off-axis and less than 3/4 mile away, built approximately 70 years after the club was incorporated. The one shot that gets a member thrown out may be the one projectile that makes the evening news and gets the club shut down.
Suburban ranges simply have no choice.
The fudds bitched about the cost, while I like our new baffles.
^^^^ This.
When I'm the RO on duty I see numerous new shooters who didn't get adequate training on safely handling guns, everything from sweeping the line, pointing it sideways or towards the sky, etc.
If all the clubs were still miles from buildings it wouldn't be such an issue, but reality is as jtnf and I stated, you can't stop encroachment unless you have the megabucks to buy up all the land within miles of a club!