I’ll start with the basics and move onto some estimates…
A single chest level alone is baseline worth something.
Possible drops are:
3, 4, 5, or 6 shards
1 legendary ingot
1 mythic ingot
2k or 4k gold
200 souls
20 glory
before being modified by your reward modifier, then rounded
before any hoard quality multipliers are applied
With 3.5 modifier (a very lowball estimate given full clears of this run from what I understand) and max hoard quality, you’d be looking, per run, missing:
11-21 shards OR 8 legendary ingots OR 8 mythic ingots OR 28-56k gold OR 1400 souls OR 140 glory
There was the off chance of getting a level 10 chest with the glitch in effect, in which case you would have lost nothing to a missing chest level, but this was, to my understanding, exceedingly uncommon.
With a lower modifier, your lost drops for a single chest level would be much less. But even straight shot runs in this faction should have yielded about a 3.0 modifier.
I don’t know the exact ratio between the drops within chests, I just know what the possible drops are. Shards are by far the most common, then ingots, and incidentals are pretty rare. So it would be pretty difficult to calculate if what you got was “fair”… unless, of course, you can work out any estimate of drop ratios where you got less of everything from the “compensation” than you would have just gotten from the resulting chest.
The lost 0.25 modifier is trickier, since the most common drops have specific break points to get one more. If you were consistently above 3.5 when the run finished, the modifier difference would have equated to about a <7% difference than having the extra 0.25 modifier, and no difference on ingots. But if you had below 3.5 with the glitch and the 0.25 would have brought you above, your average ingots were reduced by 25% (you would have gotten 8 per drop every time one dropped but you got 6 instead). For straight shot runs, your ingot amounts were probably the same regardless of this modifier being present or not, but your other loot difference would have been more pronounced, depending on just how low your modifier was.
But lets, for a moment, look at what that hypothetical model of a single lost drop for a 3.5 modifier (which in an of itself is a lowball) chest would look like, attributing the compensation to what it would relate to on the table and parse out percentages, not even looking at modifier loss:
62.5% of 11-21 shards attributed to 10 shard compensation per run
3.57% of 140 glory attributed to 5 glory compensation per run
6.25% of 8 legendary ingots attributed to 0.5 legendary ingot compensation per run
3.125% of 8 mythic ingots attributed to 0.25 mythic ingot compensation per run
0.595% of 28k-56k gold attributed to 250 gold compensation per run
1.786% of 1400 souls attributed to 25 souls compensation per run
So, even though this is hypothetical, it shows that we can directly attribute a tangible value of what could have been lost at (again, lowball) 3.5 modifier from a single drop per run, and shows that these all add up to only 77.3% of what was mailed out. And thats before we get to the missing 0.25 modifier. If we work that in, the total value of compensation mailed, assuming the drop ratios of the mailed compensation do indeed follow those of delve chests, would be about 72% of the amount missed from those that did consistent full clears (with a lowball 3.5 modifier estimate). Assuming no ingot drop break points were crossed, or it gets much worse (I don’t think they were).
Basically, it looks like they assumed kind of a slightly above average not assuming full clears (and possibly not even max hoard quality). While this might be “fair” for the “average” person, its an interesting move. From the relative “value” of each of the resources that can be given by delves in the game economy as a whole, I probably would have gone with the highest estimate and risked overcompensating people (with resources that mostly hit their value plateaus at a very low amount, larger amounts of “extras” wouldn’t significantly functionally alter any measure of “progress”) rather than have people feel slighted a second time.
Note that I didn’t participate in the event, so I’m not personally getting anything from this, nor would I benefit if the compensation were increased. I’m not generally even in favor for advocating “compensation” or anything of the like for “inconveniences”, but I don’t think this is what “as generous as possible” should look like given that it was a developer side mistake in the first place and people did spend their gems (and quite a lot of time) to participate.