If theyt put the choice to use them or keep them for later, this shouldnt be happening,
for what other purpose would people keep them, they are not doing a pretty good job on
that if its not a bug and intended that way. You won’t ever see those heart again, and im sur they are aware of it…. 0_o If they did it that way so people dont abuse the boost, its the wrong choice, making people lose reward to realise u cant keep more then 3-4heart at the sametime, will only make it worse, i dont think its an abuse, they could make the boost only work for whats in progress and not completed yet. Im disappointed.