Swap created spells

Spells take pretty long to create, but are crucial to gameplay, agreed? I've just recently completed Sherbet Towers on the goblin missions, but for the challenge I ideally wanted 2 heal spells and 1 rage spell. I already had 2 rage spells and 1 heal spell created, meaning I had to either make use of what I had or use up a rage spell; the latter being what I opted for.

My future request is for users to be able to swap spells that they have created. If the spell that they are swapping takes less time to create than the required spell then the user must wait the excess time. If the spell that they are swapping costs less than the required spell then the user must pay the excess elixir; if the spell costs less the user will not be refunded for the privilege of being able to swap their spell. Please comment your thoughts or use the poll to voice your opinion, thanks!