Agrree, good points, and looking forward, there is much to consider.
I think the main aspect for the after market ecus is they are accessible. If the old ecus were accessible everybody would be tuning them, as it is already in there, much like anything that is OBD these days... Of course the technology has moved on, but for the majority of people and applications they wouldn't tell the difference, certainly nothing sub 6500 / 7000 rpm. I can see it from both sides as I can reprogramme the old ecus and have done successfully, but on balance in a trader situation you could not afford to spend the time I have to get to that position, would never make sense, and I do and would select aftermarket if the additional functionality of coil packs, launch control, anti-lag, and programmable boost control were needed individually or combination there of. If not, it then really only cones down to accessibility... once the atomised fuel is in the cylinder, you only have firing the spark, the engine doesn't know anything else... the tuning is in the rest of the hardware in reality, once you have optimised fuel and timing, there is nothing else you can do with the ecu. I don't know if anyone has cracked maintaining the signals to the on-board computer with an aftermarket ecu, pretty sure the guys in Europe haven't cracked it yet, or simply not bothered, pity really. If you are racing it doesn't matter, but I guess more of an issue for the A610 and OE spec owners?
Hardware wise... yeah, the build is just cheap... horrid in the way it was done, the joints mid loom, nasty unscreened tacho signals running up and down, loop backs everywhere, and multiple connections all over the place... but hey ho... So anything that improves this situation is good, and real benefit to improving and maintaining the integrity of the cars long term.
I'm pretty sure the nuisance cut can be cured as the fuel relay pull down ouput from the ecu is only dropped for a limited number of reasons. The ecu enables the relay by pulling the output down to ground, and the circuit is mostly hardware than software based. The sensor fault cut counter I mentioned is for specific faults, and the count is simply increment to a trip level, it only appears to cut the output at idle, and this is set at threshold of around 1000 rpm, past this point this behaviour is disabled. Likely to stop a mistuned engine creating emissions at idle for extended periods. I haven't hooked up to the fault diagnostic socket at the same time to see what was going on however. I will look at the code again, and give you all the list of sensors, because it is not all of them, and you can then hone down to those items reducing scope. The wire from the ecu to the relay is less than a couple of feet long, and a strap connected in the middle as BigM has, proves anything mid return wire through the relay out to the positive feed is 100%, so it's either a out of spec signal into the ecu, or the ecu itself causing the problem. The ground return for the relay is the same for the ecu, so it is not that either; a missing return on the ecu, and it would drop all it's drive signals including ignition, and hence a fault on this path would still result in the strapped cars cutting out, which it doesn't.
Nothing is 100% safe, it would be imposible to live, and in fact everything these days is worked out on the basis of acceptable risk, and as low as reasonably practical...