I don't know about the grid rules, but it sounds like they are thinking you may be able to do some type of work at this time.

A main point for SSDI is not what your condition or diagnosis is, it is are you able to work at some sort of gainful employment similar or different type of work.
How COPD affects you day to day..is the important part ..more paperwork or drs records/notes may help..

There are useful sticky threads the main SSDI page, very helpful information-
https://www.neurotalk.org/forum28/