I think that every transformative should be guaranteed to trigger at least one transformation each time you use it if there are still transformations which can trigger. This gripe is being brought about by the Nuki Cookies, which has a chance to just not trigger a transformation, even with loads of transformations still available. This is nothing but an annoying waste of time, because all it actually means is that I have to leave the inventory, save, and pull the inventory back open after every use so that any wasted usages can be undone.
Does it make sense that some cheap transformatives would be unreliable? Yes. Is it enjoyable? No.