The caution I would offer with taking rescues is that the poultry world has a lot of really nasty diseases with very few effective vaccines and treatments. The current discussions about respiratory diseases makes the point here better than I ever could. Quarantine sounds good, but is, in truth, ineffective, as many diseases can reside in birds with no symptoms for months, years, their entire lives, but still be able to pass those disease agents on to other birds.
I think if you take in enough rescues you will accumulate all the nastiest diseases and they will take out most of the birds you are trying to save.
That is a pretty grim assessment, but in practice, poultry rescues are nothing at all like dog and cat rescues, where pretty much every disease is preventable and treatable. The state of poultry medicine is not even close to that, poultry are usually culled when they get ill as they are regarded as livestock by the vet practices and schools (as a rule). I applaud your intent and hope it works out for you better than my predictions here.