For those interested in how well this mod has worked in probably the most chaotic and abusive DCS layout in the world... Here's 7 months of data I just transcribed. We had one channel fail one time in June, but that was due to one of the clamp diodes coming off the board becasue of my poor soldering. We glue them down now.
Anyways, seems pretty reliable compared to the chart way at the top of the post. I'd say with this much testing, it's clear the solution is good.