I'm waffling on some interpretations regarding the Order of Scribes wizard subclass in Tasha's Cauldron of Everything, and would really appreciate some second opinions. Most of the features seem pretty straightforward in their application, but as usual, I think there are some edge-case spells with more than one reasonable interpretation.
The description of the Order of Scribes wizard's 6th-level feature Manifest Mind says, in part (TCE, p. 77; emphasis mine):
[...] As a bonus action while the book is on your person, you can cause the mind to manifest as a Tiny spectral object, hovering in an unoccupied space of your choice within 60 feet of you. The spectral mind is intangible and doesn't occupy its space, and it sheds dim light in a 10-foot radius.
Whenever you cast a wizard spell on your turn, you can cast it as if you were in the spectral mind's space, instead of your own, using its senses. You can do so a number of times per day equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.
[...] The spectral mind stops manifesting if it is ever more than 300 feet away from you [...]
How this interacts with the Mage Hand and Unseen Servant spells is not so clear to me at all. Let's stick with Mage Hand for the purpose of simplicity, though both spells have similar language to:
The hand vanishes if it is ever more than 30 feet away from you.
Obviously everything works as expected within the normal range restrictions (say, through a keyhole, then send it behind a bookshelf).
But what if the spectral mind from Manifest Mind is 100 feet away? You can obviously conjure the Mage Hand through the spectral mind, but does it vanish before you can spend an action to have it do anything? Is this Mage Hand tethered to your physical location, or is it tethered to the spectral mind's location since you cast it as if you were in that space?
If you use the Manifest Mind feature to cast the Mage Hand spell from the spectral mind's space while it's more than 30 feet away from you, what happens?
I would appreciate any references I may have missed that would clarify my uncertainties.