How are multi word synonyms supposed to work in EPiServer Find?

Hi, we have a case with a customer who wonders whether they can map multiple word phrases to synonyms. I thought yes, but that does not seem to be the case after some experimentation. So the question is whether this particular use case is not supported or if we have made some error when setting up the client.

The use case:

Given the synonym mapping skjuta upp, förhala, senarelägga <> prokrastinera

When searching for skjuta upp

Then I should get results including pages containing prokrastinera

This does not work in the case of skjuta upp. The single words works as expected, though.

The client setup

var find = SearchClient.Instance
    .UnifiedSearch(Language.Swedish)
    .For(query)
    .WithAndAsDefaultOperator()
    .UsingSynonyms()
    .ApplyBestBets();

So, can you use multiple words in the phrase field or is it only supported in the synonym field of the synonym settings view?

/David