I have Inogen Rov 6 and Inogen One G5. Settings are 1-6 in pulse flow. My prescription is 2L continuous flow which is a common starting point. For exertion I use my Inogen and I set it at 6 when on the treadmill. For going to the store I set it at 4 to conserve battery.
I bought a backpack and that really helps to distribute the weight better. I have given up large purses!
I am 55% predicted for TLC and 59% predicted for FEV