Doha Lounge access

[PapaChurn]

Hi,

Will be flying into Doha from HK in first class and then departing in economy onwards to europe (unfortunately got downgraded after the original flight got cancelled).
The Al Safwa lounge entry rules seem a little vague. It would appear if you arrive with valid inbound boarding pass in first and leave in business you will be allowed access to Al Safwa. Does anyone have personal experience where the outbound flight is in economy?

Thanks