TLDR - Have the Mega D1sks weight 5x more points than the Standard D1sks on the individual stretch goals rewards and tune down the cumulative rewards by alternating between Mega D1sks and Standard D1sks given.
I think in regards to the individual stretch goal points it's pretty straightforward it was a bad implementation in wave 2 promoting only the Standard D1sks to be bought to take advantage of the cumulative Mega D1sks bonus .
There's already a discussion thread for this presented by @cyan zealot :
This idea thread is more to hash out the details on what should be the difference in points between Standard D1sks and Mega D1sks.
The idea is to attribute different weight to the points given by d1sks according to their price.
Since a Standard D1sk is 0.003 eth and a Mega D1sk 0.018 eth, this would give an equivalent number of 4.167 Mega D1sks (0.003 * 25 / 0.018).
My suggestion is to give Mega D1sks a 5x multiplier in points to round things up. This would mean that for every 25 Standard D1sks or 5 Mega D1sks you would get 1 free wave 4 Mega D1sk.
Now the next question is the frequency of these bonuses.
It's safe to say that this is a good incentive to buy D1sks and it tremendously help wave 2 numbers, maybe a little too good, but they also have the advantage of guaranteeing X number of D1sks for the next wave. This bodes well with the alpha sale change idea in order to more accurately predict the number of alpha D1sks to be sold.
There will be 5931 wave 3 Mega D1sks given out for free (roughly 25% of the total wave 2 Mega D1sks sold)
My suggestion for this as to not inflate only the Mega D1sks for the next wave would be to throw a mix of standards and megas and lower the cadence of getting these rewards.
For example, alternating in giving 1 Standard D1sk or 1 Mega D1sk for every 25 points ( 25 standards or 5 megas).
Let's make Illuvium Beyond Great Again!