You know, gender swapping magecraft isn't as silly a route to the root as one might think. Many myths describe prototypical humans as possessing aspects of both genders before being divided. So the gender bender magecraft might have been an attempt to attain that primordial state.
@Chaosfox The official Daily Chaldea comic lore is that the original strategy was pursuing body-modification magecraft to see if they could recreate parts of creatures from the Age of the Gods (like Artoria's dragon heart) and access ancient powers that way. However, they didn't manage to reach that kind of destination. Instead, they ultimately ended up with the Genderswap spell as a dead-end power. No matter how much time they spend researching it, it will never be able to reach the Root or even change significantly from the form it already has. (...In other words, I wanted to avoid giving giving the protagonist extra superpowers, beyond what's presented in-game. XD)