Fivetran bring in most data, enough to build a call utilisation picture. However, when we look at the call utilisation, we do not have enough detail of user statuses to determine whether it was due to extended breaks, or due to back-office/after-call actions/meetings/training.

Aircall provides detailed user statuses /v1/users/:id/availability. These are  need but are not available via Fivetran
Aircall provide an API call "Retrieve list of users' availability" [link] that seems to provide what has been requested. `GET /v1/users/availabilities`.