Don't support. :/
What would be the point of recycling eggs if we were just going to make it possible to get one of the creatu at any time? We may as well stock them all at once and forget about rotating them monthly. The point of rotating them is to regulate the creatu's appearances into the game and keep them from exploding. Being abel to change them at will would just tip the scales. Granted, yes, it would be a random generation, but there's a small number of CS creatu that you'd have to get.
Beans stay in the CS constantly and their colour generation is random, but have a percentage. You can't control what you get, but you won't get 15 albinos from 20 beans becasue of how the colours are generated through the percentages. If we did this, we would have to set up something that would create some sort of hinderance, just like what the beans do.
If we WERE going to do this, then I would suggest a fail rate of the potion actually working, but if we did that, then no one would bother spending their money or tu on it just to risk the chance of the transformation failing.