my current h1b extension is pending with USCIS and I am working under 240 day rule with my current employer A and 240 day expires by Jan 15, 2020. I got a job offer from employer B who is also willing to do the h1 transfer. My questions are
1. Is it safe to wait with the current employer h1 extension or go with the new employer h1 transfer extension?
2. What happens if employer A application gets approved before Employer B or vice versa?
3. If employer A's application gets denied, can employer B still file H1 petition

I really appreciate your help.

P.S. My extension was filed on December 13, 2018 and received an RFE and submitted the RFE documents by June 11, 2019 and the application is still pending.