I don't get Half Dome permits as currently implemented. There are smart people at the NPS so why can't they look at the underlying causes of those deaths (people on the cables during late afternoon thunderstorms - not due to lightening, I only know of one lightening death on HD, but from slipping on wet rock). Instead they look at correlations - deaths on 800+ visitation days (which slows down everyone's travel and results in more people on the cables in late afternoon).
My idea/wish/desire/comment to the NPS: There's one right way to climb HD in the summer, IMNSHO: leave early. 5 am is great. 6 am is okay. 7 am not so good. Those deaths? I'm pretty sure they were all/most all of people who left at 9 and 10 and 11 am. Which meant they hiked in the heat of the day, in full sun, went slower because of it, and were on the cables in the late afternoon. Late afternoon is when the Sierra has its thunderstorms and is essentially the only time that rock is wet from May to September.
My proposed system: Anyone can print out a "permit" from a website. It explains the rules and gives safety guidelines. There's a time/date-stamp machine at Happy Isles. You must be within the first 200 people if you get your permit time-stamped AFTER 7 am. If you get time-stamped before 7 am, there's no limit. If you have a backpacking permit (which already have their own quotas) for a different trailhead, you are also allowed. Maybe there's a time-stamp machine in LYV for those backpacking to ensure they too get an early start.
This would mean far fewer people there in the dangerous afternoon then the current permit system (400 with no time constraint, so many start late) AND it would allow more people to see/enjoy/challenge themselves on this iconic hike.
It would cost almost nothing to administrate, nothing to hikers, and be easy to enforce - proper time-stamp: you're good, no time-stamp: expensive fine.
It would be to my personal detriment, because in addition to beating the sun and the heat, I also like beating the crowds. My last time up, I saw NO ONE the whole way and only 6 people joined me on top before I left at sunrise (I hit the trail at 2 am).