I see that, gems ratio per board cannot be guaranteed and collecting keys also needs to be in same ratio per each color keys. What I meant was, keys obtained to open chest (3/6/9) cannot be matched with reset energy spend. Need to correct the sentence in my earlier comment. That's not a conceptual comparison or analysis.
It's true he's a bit optimistic about "only gold ratio" on the chests - but from playing around with what it takes to dump extra fire keys earlier in the event, I think about 90% of gold ratio is accomplishable on average - and have erased fire surpluses multiple times over the event without issue to feel it's consistent to do so.
I find his 140 energy per board to be a bit high though - so I think you can actually get more boards than he went with - lower keys/board but more keys/energy overall.
My working averages: 106.1 energy per board, 20.6 gems freed per board, 17.9 keys per board, 1.15 progress / key (gold is 1.28).
22 days of 3 resets per board :
67 boards
60*22 resets
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total: 8323 energy for 1380 progress + 1199 keys for 1379 progress = 2718.
Additional boards will be added at a cost of an 80 reset + 106.1 = 186.1 energy. 2200 spare energy gives us: 11 of those = 227 progress + 197 keys for 227 progress = 554.
So we're up to 3272 without any unreasonable luck demands.
Now we add in 20*9 = 180 keys (generally you only have 20 days of the daily special being the special one in an event ; the first and last day are both ineligible). 207 progress.
And 21 double chests (maybe 22, don't remember if the first day had a double chest or not) : 21 * 23 = 483 progress.
2718 + 554 + 207 + 483 = 3962. With a cushion of 5% for bad luck/choices
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But what we're focused on shouldn't just be possibility, but *plausibility* - very few players are going to play the event to that degree of accuracy! Hell, *I* wouldn't have without playing it on beta first! So while it's *possible*, it should still be improved some so that it's *likely* for your average player that makes some amount of error in their play