I will personally try some unflavored. I haven't tried any yet. There are many benefits to vaping, but there is also good evidence that components within some of our favorite flavorings are responsible for irreversible lung damage. What a shame it would be to reduce the cancer risk almost to zero, no longer have lung tar, no longer smell bad, finally be able to control nicotine levels, and at the end of the day we still end up with COPD or worse lung damage.
If someone vapes diketones at the levels that are contained in some of these juices, I just don't see how lung damage is at all avoidable. It seems like more of a matter of "how long will it take" rather than "will it happen".
If smokers get mild to severe COPD, and if diketones play a roll in that, then vaping more of these chemicals in our juice than we used to get from smoking does not look to be very promising for our harm reduction goals.
Some people say "well this is vaping, so maybe its somehow not harmful to have DA/AP in the juice". If diketones contact your lung tissue, they are causing damage to it. Vaping diketones causes them to contact your lung tissue. It is safe to assume there is damage occurring, and very unsafe to assuming anything else.
I also like the idea of cutting back on flavoring in the same way you cut back on nicotine. That's a good idea. Use the flavorings and strong nice to get you off the smokes, and then taper off to make it even safer as you continue to adjust.