Thanks for answering, you're awesome!
Good to know re End Run, thanks!
Re the timing, my gut says this is more of a bug than an accuracy or timer/clock issue. After all, the other 'Build Keystone' buttons did their job, I can now travel in a few seconds something that was taking 40-60 seconds; this one is not making any difference at all to travel time, it's literally not reducing travel time one bit, and that's not just a clock thing, that's an issue with the travel time reduction code... a timer issue would be a problem of fractions of a second ie milliseconds... this is a problem of 4-5 seconds!
Alright, I got to the bottom of it. There was a bug with how very fast tasks were being timed, which is now fixed. The issue you were seeing above wasn't related, it's a math thing.
The speed a task is done at isn't linear, it's exponential based on the skill level. That means that the first 10/25/50% of the task takes a lot longer than the last 10/25/50%, because your level went up while doing it.
Taking off 10% of the work to be done can be thought of as taking it off of the end, when the task is being done the fastest. That explains why there isn't a 1:1 conversion of work required:time taken.
Either way, it's still worth it to build keystones. Thanks for pointing it out, I got to bust out the old Excel sheets!
Thanks for that.
Sadly, I've tried and I've built another 5 Keystones at that point, and I'm still getting there with 25.35 seconds left, plus or minus 0.2 seconds, so the Keystone is just not cutting travel time even by 1 second. Even if I throw every rounder I have at it, I don't have enough time to do the next steps, so I'm officially stuck. I suppose I could wipe the save data and go back to the beginning, and see if that makes a difference, but... I've rebuilt my rounders so many times, I'm just... yeah. But thank you for a great game, good luck with the progress, maybe I'll come back to it some time.