yeah .. thinking back, Portal Profit spells are one of the major errors done by Inno. This spell should have been RARE with only 5% and extremely rare with 10%. So rare that we keep it in Inventory to use it only when was a dramatical shortage of something, not to swim in PPs. I see players who went through chapters like the wind, having only the portal and doing almost nothing, having almost 0 understanding of the game but then complaining about "how did you get so many wonder leveeeeelllssss!?!? If I say that I play for 5 years and they play only for 2, they don't find this as a reasonable answer.
Now, because of this abundance of PPs, we get weird new chapters with weird requirements and weird story-line quests, just to compensate the overflowing of PPs.