It was just a pity that this involved the concept of "space" after all.
Don't be fooled by those spellcasters' low Levels and their ability to cast all kinds of summoning and Teleportation type Spells; that's only them pouring Spiritual Magic Power into pre‑memorized Magic Models. It doesn't mean they've done any real research into the concept of "space" itself.
It's like a veteran who has fought on the frontline for many years: he might be able to use and even disassemble a gun with incredible Skill, but if you tell him to create a qualified gun from nothing while standing in front of factory machinery, few people could actually do it.
The difficulty of using Spells involving the concept of space and the difficulty of making space‑type items are worlds apart.
Under these circumstances, even though the number of spellcasters on the Aifala Continent is very large, space‑type Tools have never become common.
