Oh boy…a 9 bone ribeye roast is one big sub-primal! I sure hope that you took precautions to protect the UMAi Dry® bag from ripping!
Anyway…9 bone or even a previous 9 bone roast either way is a very thick piece of beef! Being that thick 28 days is “nothing”! $5 days will give you MUCH better results and appreciation for dry aged beef!
Trying to reuse a bag – even being super careful will be hard to do, much less be successful.