Okay so i wrote a suggestion below. This started out as a no-brainer but i put some thinking in this while writing it, edited a thousand times but it might just have massive advantages and eliminate many disadvantages that we currently have. So hear me out on this for a sec and try to read everything, it took some time to fully develop this idea:
Imagine having an IPO, but instead of distributing another 500k harmony for the IPO, you could just use the harmony that was supposed to be swapped for yin/yang, and for every harmony bought as IPO you (the team) just buy 8 yin or yang from Pol with the money received from the IPO investor.
To give an example: An investor wants to buy 10k harmony of the IPO, say at a fixed price of 3000 sat per harmony. He pays you (YinCoinYangCoin/the team) 0.3 BTC for this and you give him 10k harmony that was supposed to be swapped for 80k yin or yang. So, now you buy 80k yin or yang from the market (with the money you received) at the lowest price possible, and 'destroy' these. Now in case you buy the yin yang from Pol in the range of 1-375 sat (375=3000/8), you will:
1. have eliminated the yinyang of dumpers who would've dumped their harmony for under 3000 sat (the IPO price) after the swap (i'm explaining this below)
2. instead of people dumping during the Harmony phase, coins will be dumped prior to this: they'll dump in the yinyang phase
3. this will not cost you money, you'll actually make a profit from dumpers selling yinyang under 375 sat
4. profit can be used for mintpal etc.
In case there are no more people selling their yinyang under 375 sat after a while, this wouldn't be a problem (on the contrary!): It would mean you eliminated all dumpers who were going to dump harmony for less than the IPO (< 3000 sat). Because they're better off selling yinyang at around 375, instead of dumping cheap (< 3000 sat) harmony after the swap. (So IF many people will sell yinyang at 375 sat and not lower than that anymore, it'll create such an overflood of sales at 375 that there'll be a lot of competition amongst sellers, thus naturally generating lower prices. Even IF, theoretically, this competition wouldn't happen and it'll only be sold at 375 and not lower, it would still eliminate dumpers too so wouldn't be a problem.)
Some more advantages:
-There will be less yinyang holders, so less swap (this is what the creator wants!)
-The fact that yinyang will be swapped for harmony, will no longer have such a negative aspect since yinyang will be worth something again.
-Harmony won't be a replacement for a 'dead' currency: there'll be put life in yinyang again prior to its artificial destroyment by the swap, healing its reputation (thus healing the reputation of the creator, the team and ofcourse: harmony).
-If yinyang sells for around 375 sat after a while (which is very possible as long as the IPO is succesful), the IPO investors will NOT have the disadvantage that yinyang holders will get their harmony way cheaper (as of now yinyangholders will get Harmony for about 800 sat, since yinyang's currently about 100 sat). It would be unfair for the IPO investors, as you mentioned before, since they spend 3000 sat. With my idea, if yinyang naturally gets to about 375 or more in good conditions, this disadvantage will be eliminated aswell. Yinyang holders pay about the same price now so it's equal, plus they can gain profit if they don't dump this time (this would be a first for yinyang...!). If it doesn't make the 375 sat, still some dumpers will be eliminated and it'll still have a positive impact, with even more profit to spend on mintpal (win-win situation).
Note: ofcourse you (the team) are supposed to buy yinyang from the community for this to work. If you use your own yinyang (or from the team) you wouldn't eliminate the dumpers thus have no effect with this.
Note2: in the beginning, when yinyang will be < 375 sat, people will prefer to buy yinyang instead of IPO. This can be avoided by several ways: the team can already start buying cheap yinyang on Pol, the community can do this too. People outside the community can too: they'll see it as an investment after this plan has been announced. With stable floor of 3000 sat for harmony they have a good investment if they buy yinyang below 375 sat, even if they can't sell it for 375 (if it doesn't sell they'll still have the posibility to swap).
Afterwards the swap can go as planned with the remaining yinyang, without the dumpers. You could even scratch the 'one week waiting time' for the swap to satisfy everybody in the community because a floor of 3000 sat will be set and will be way more stable. No more fear for dumpers.
Looks pretty solid if you are able to find a not too high - not too low IPO price. If it's too high, you get less investors, less dumpers eliminated and less chance of yinyang to reach 1/8th of the IPO price. Too low and still too many people will hold their yinyang as yinyang will reach 1/8th faster. So the one crucial task the team has, if this plan gets implemented, is making sure they're able to get enough people to get in the IPO. The positive aspect about my plan, is that the plan itself should make IPO more attractive for investors.