Is Hex worth it at high levels?

[Theodoxus]

It's not a ruling. You aren't casting anything, subtly or otherwise, when you're moving the curse.

"...you can use a bonus action on a subsequent turn of your to curse a new creature."

You're cursing the new creature, just as you did the first. Technically, it requires VSM to do it. Or, do you think it's purely psychic in nature? To state otherwise is a ruling. It's fine. It's not, however, how the spell is written.