Joe, those are good points. Let me express a few thoughts.
First off, I am not affiliated with SMT and do not speak for anyone by myself. This was my first exposure to ETs, but because I've been in IT for 45+ years, I take to technology like a fish to water. I used the system for the MR team match, then the LR individuals and the LR team match. I was using my own tablet for LR team match and when I was not shooting on Saturday, I was using my tablet to look at other targets and review stuff. I also spent some time with the SMT tech guy discussing the technology and its implementation and how it runs on Linux. That does not make me an expert in anything to do with this, but I have an understanding.
There is no paper audit trail. The targets are constantly raised and ready for shooting. The system is always accepting shots and it records the shots fired as long as they are supersonic at the target. Each shot is recorded on the Linux system with time, target number, the time differentials for the 8 microphones, the temperature (needed to calculate SOS as the only thing that affects SOS is temperature, (yeah, I know humidity can have a slight effect, but it's immaterial)) score, velocity, etc.
When there is a crossfire, it's quite similar to the way it works now. The scorer observes that the shooter fired a shot and nothing is displayed on the target. In other words, the shooter fired and missed the target. If it was a crossfire, the shooter/scorer pair of the target that received the extra shot will detect that a shot was recorded that was not fired by the shooter of that target. Just like we do now with manned targets. The offending shooter gets a 0 and the affected shooter does not get the shot recorded. Of course, if the two shots appear simultaneously, the affected shooter should get the higher score. This would only occur if it was difficult or impossible to determine when the errant shot came in. The line officers helped make the necessary corrections on the tablets.
The only paper trail is the scorer writing down the score as recorded by the system after each shot. That's not much of a backup, but you can record irregularities on there to be traced later.
A friend had a crossfire when he shot on the target next to his. There was no shooter on the target at that time, but the errant shot was recorded and so my friend knows that he did in fact shoot on the wrong target, like that's any consolation.
As for the download of the scores after the fact. We can do that now and I am in fact transferring my data to a spreadsheet for analysis. The one thing I have a problem with is that the generated PDF does not allow me to see all my shots properly as they conglomerate on the 10 and X and cover each other after a while. The 9s or worse, are all too visible, but perhaps that's enough. I did discuss with SMT the possibility of getting more useful data in terms of coordinates, the discussion continues.
Unlike you, I do believe this is a workable system. We just shot a very large match using this system and overall it worked quite well. I have no doubt there will be variations on this system and maybe different technologies in use, such as your optical dream. However, the acoustic system is neat in that it gives you the velocity of your bullet at the target, something that an optical system will be hard pressed to do. Also, the optical system would have to have a sensor placed in front of it, smack dab in the middle, that would expose it to incoming jacketed lead. The microphones are on the sides and are not in the incoming flight path.
The market is relatively small for such devices so, I would not hold my breath waiting for someone else to step up. Then again, now that someone has come up with a working system, it may spur someone else to try another method.