It does seem like we need to take a page from those wise bacteria: You can't survive in space without genetic modification
The question is, when will humanity become wise enough to catch up with the technology? Probably never.
Wise enough, never.
Smart enough, we already are.
Sadly, we're not both at the same time and the results are in one of the Sci-fi books.
It would probably only take one or two generations to adapt, if the offspring dies before reproductive age - evolution is cruel, but it can be effective.
Evolution takes a lot longer than a couple of generations to make effective changes.
Unfortunately bacteria reproduce and evolve much faster than we can, so for practical purposes we likely can't really genetically engineer our way out of this
I wonder if a small scale centrifuge (think hospital bed on an office chair) could be useful to flush out the liquid content of the lungs every few hours?
Space is a big issue, to subject the person's whole body to the force in the same direction you'd need it to be at least 2x larger around than the tallest person you're going to send through it which AFAIK isn't possible anywhere on the ISS at the moment. BEAM may have had just enough space before it was converted to a cargo module.
That's why I was suggesting just an office chair and a hospital gurney - to flush out the lungs, you probably don't need to worry about making the whole person experience uniform spin gravity, just shake it out of the lungs!
You could maybe have them kneel on a spinning platform instead but I think you would still want their head on the same side of the rotation axis as their feet for example. Also I wonder how long you'd need to do this to allow the body to properly clear the built up fluids.