Hello all, This may not be useful to all but I was diagnosed with IPF in Jan 2016. In 2017 my wife made a trip to Brisbane Australia when my FVC was 75%. We flew from LA to Brisbane, a 13+ hour flight. I have a POC with a 9 hour battery at 2l. I would use it for awhile, turn it down to 1l, then turn it off for a while. we made it to Brisbane with no ill effects that I know off. Not sure if I could do it now that I am down to 70% FVC. We had the time of our lives, Helmet diving on the reef, flying to Perth, taking the Indian/Pacific railroad to Sydney then a cruse ship to Seattle Wash.
Life is now to short to not do what you want if your Doctor says it OK.
Ken