Calling this glitchless is a little misleading, unless you’re suggesting that carrying spells over from one run to the next was intended / normal functionality.
I would definitely argue that this is intended. Hollow eggs have all kinds of weird abilities and are extremely important to the lore. And the wand is also completely possibe to build ingame unless I missed something. So while extremely unlikely this is theoretically possible.
Of course you are right, this is not a standard speedrun. But i still think it is insane and very cool.