Just completed half of my trip. Firstly I had a schedule change that allowed me to change the destination to BKK instead of SGN. At PNH I was surprised with a Qsuite on PNH-DOH (Dec 18). It was a superb flight with amazing service. Actually Qsuites were showing on a seat map since I booked the flights but I didn’t believe it until I boarded the plane. Then made an immediate turnaround at DOH to BKK on A380.
Also I positioned to PNH with QR a day earlier from EU. I am not sure if turnaround at PNH the same day would be possible without visa. Upon disembarking there was only one corridor leading directly to immigration. Though there was a staff available and maybe they would allow transit without visa (different corridor would have to be open by them). The airport wasn’t busy and visa collection and immigration was a matter of minutes so in the worst case there is enough time to enter and leave the country.