Does piety work across planes?

Mythic Odysseys of Theros introduces the concept of Piety:

The strength of your devotion to your god is measured by your piety score. As you increase that score, you gain blessings from your god.

Nowhere does it mention if this is limited to a character’s presence on the plane of Theros, where the gods reside.

While the source book doesn’t mention moving between planes, is there any indication that this piety stops if the characters leave that plane? I’m asking in the context of the Magic: the Gathering setting where interplanar travel is possible.

My default assumption is that it’s unspecified and possibly unanswerable, but I’m happy to be proven right/wrong.