Partial prefix search on FLE encrypted fields

I have a users collection having fields like name, phone and email. I a, currently use prefix regex search to support the substring search on these fields.
For example to return a user object with email testemail@test.com we could search with tes, test, teste, testem etc on email key using regex search.

I was planning to use field level encryption on these fields to encrypt the personal information. How would I be able to support this use case?
I have considered storing all these prefixes in an array, but turns out FLE doesn’t support deterministic encryption on arrays and using random encryption would make them non queryable.