A couple random thoughts on pulmonary rehab not exactly answering your question.

The 6 minute walk test is used for determining eligibility for PR at my place. It involves walking as quickly as you can from orange cone to orange cone set up a certain distance away. You are timed. I did not qualify but after my last infection (walking pneumonia) I put myself on a home rehab program, which involves using an incentive spirometer, treadmill and upper body dumb bell weights.

I've also noticed that there are PR programs available online with more and more of them supported by insurance.