There are thousands of Asylum-based I-485 every month handled by thousands of employees, each employee has their own factors and decisions and processes and absurd stuff hahhaha; there's really no golden rule or standard. We definitely hope the RFE means you're very close to it; sometimes it takes way less than 1 month, sometimes it takes way more. My other piece of advice is that researching too much, while very tempting (trust me, I have been there hahahaha), will leave you more anxious and disappointed in case your timeline doesn't fit what you saw. Trust me, even if it does not fit what you saw, you're in great shape!