How I read it is that you specify which ways you will use a column and then VT will create the various encrypted columns to support this. Deterministic shared key for matches only. Ordered encryption for ranges and FHE for various calculations. The latter probably being quite slow. I don’t think they are rolling their own crypto, just combining a lot of existing algorithms in various ways.

I could see a use cases in either defense in depth and/or storing data in the cloud while having your keys somewhere else.