Pulled logs from my mains, 1690 total chests opened.
46 loud thud
274 thud
1370 noise
So, we can roughly assume:
1370/1690 * 50k = 40,533g
274/1690 * 300k = 48,639g
46/1690 * 20m = 544,379g
Thus, a chest is worth ~633,551g using YOUR values.
Now, let's look at your strategy.
Pt1: Open after 3 thuds.
3 Thuds, 2 noises (5 chests) : 1M value + 633,551 from final chest.
80% chance of success * 633,551g = +506,841g
20% chance of fail * -1,633,551g = -326,710g
In this case, you stand to make 180,131g on average by opening a 6th chest. Guess your strategy made the wrong choice.
Pt2: Open after 7 chests.
6 noises, 1 thud (7 chests) : 600k value + 633,551 from final chest.
2/3 chance of success * 633,551 = 422,367g
1/3 chance of failure * -1,233,551 = -411,184g
In this case, you stand to make 11,183g on average by opening an 8th chest. Guess your strategy was wrong again. In the event of 7 noises, it is 94,517g.
Pt3: Open after 1 loud thud.
This is correct, but everyone already knows it. Even if it's the first chest:
8/9 chance of success * 633,551 = +563,156g
1/9 chance of fail * 20,633,551 = -2,292,617g
Lose 1,729,461g on average by opening that second chest.
I AM NOT CLAIMING THESE NUMBERS ARE ACCURATE. I AM USING SORALIN'S VALUES PER CHEST TO ILLUSTRATE THAT HIS STRATEGY DOESN'T EVEN MATCH HIS OWN NUMBERS.
The truth is that you'd need tens of thousands of runs correctly logged to actually know with any certainty. Obviously a chest type doesn't average to 50k, 300k, 20m on the nose. I don't think they're even close. Further, we have exceedingly little information about the actual distribution within the final chest. But, fact is, we don't have the data and soralin's conclusions are drawn off emotion and feeling, not numbers.