What is the I-526 RFE response time for EB-5?

You have an additional 60 days to respond to the RFE per the COVID-19 flexibility policy of USCIS: https://www.uscis.gov/newsroom/alerts/uscis-extends-flexibility-for-responding-to-agency-requests

That is correct. USCIS, in 2020 due to the pandemic, extended RFE deadlines by 60 days (they, of course, printed the classic 90-day timeline on the RFE themselves, not the additional 60 but that is USCIS for you). This flexibility has been extended several more times since, and even now RFEs have a bonus 60 days to respond past the printed date on the RFE.

Yes, you will have additional 60 days to respond to the RFE.

You get another 60 days to reply as USCIS extended the flexibilities it announced on March 30, 2020, to assist applicants replying to Requests for Evidence. USCIS will consider a response to the RFE received within 60 calendar days after the response due date set in the request before taking any action.

There may be flexibility in responding to RFE deadlines, but good luck with getting any kind of uniform response time from USCIS when it comes to adjudicating RFE responses. We used to hear back from USCIS in 6 months or less for years, but now it is all over the board (unless you want to sue and force them to answer).

Yes, it does.