Does basic rule allow almanac offsets? Ie sunset + or - If so sunset minus x hours so it will trigger at a more convenient time. But your issue is not the on at sunset trigger but the off after waiting. Get it working then modify it to suit. Just trying to save you some time.
Although, the trigger isn't the problem here. Run Actions is identical to the rule being triggered, but for the trigger itself. So there's really no reason to mess around with the trigger.
Here my reference to an almanac refers calculating events in this case sun rise and set. But also moon phases, Ebb and flow of tides, and the changing of seasons. So sun(set/rise) offset. Turn on the outside lights at Sunset +15 minutes and turn them off at Sunrise -15 minutes.
I believe the issue was that I was testing this rule AFTER sunset, so that initial trigger never fired off, as someone in this thread suggested. It's working now!
Another strategy is to trigger at the on time and another trigger at the off time with a little test in the rules to sort out what to do. That way there is no running timer to get canceled. But you got it working and know how not to break it. The more we do with hubitat the more we learn.
There is no such thing as a 'running timer'. There is a scheduled job resulting from the Wait. Your solution also involves a scheduled job, for the second trigger, but then burdens the rule with extra logic to figure out what is going on.