It would seem QR now permits early checkin at Jewel up to 5 pm, just in time to stride over as the lounge opens at 6 pm.
https://www.changiairport.com/en/air...in-online.html
Available for travellers flying with:
- Qatar Airways (Selected destinations – Austria, Australia, Afghanistan, Albania, Argentina, Armenia, Bahrain, Bosnia, Bulgaria, Belgium, Costa Rica, Croatia, Czech Republic, Congo, Cyprus, Denmark, Estonia, Egypt, France, Finland, Germany, Georgia, Greece, Grenada, Gabon, Hungary, Iceland, Ireland, Italy, Netherlands, Jamaica, Kazakhstan, Kyrgyzstan, Kuwait, Latvia, Lithuania, Nambia, Malta, Mexico, Moldova, Mongolia, Montenegro, Oman, Poland, Portugal, Romania, Rwanda, Saudi Arabia, Serbia, Slovenia, South Africa, Sudan, Sweden, Switzerland, Turkey, Trinidad and Tobago, United Kingdom, and Yemen)