Hello Aaslestad,
The cloud processing always returns 50% when the processing is in progress. In the current implementation the estimated time is not returned to the program interface, as it may very due to the number of nodes working on the project.
When the status is "processing in progress", you can safely disconnect. After the processing is completed (you can see that in the personal account page) you can re-open the project and the data will be synchronized with you local project files.