Celsius pays interest on crypto deposits, so there is some difference with other standard tx types from exchanges, maybe.
Yes, we've been talking to Celsius about this for several weeks.
At this moment Celsius does not offer CSV exports or a read-only API, but they are working on both.
However, they told us that users can contact their Support Desk and their devs will create a CSV.
Unfortunately we don't know what the CSV format is like. But you should be able to import it via the Custom Exchange import.
As soon they provide a real export function, we will integrate Celsius.