There is a single engine diversion speed restriction on the airplane applied by Airworthiness Directive 2018-08-03 to avoid single engine operation of the remaining engine in a condition that can cause compressor blade resonance and resultant engine failure. The same AD limited certain RR powered 787s to a 140 minute diversion time. The AD applied those restrictions via AFM limitations.
http://rgl.faa.gov/Regulatory_and_Gu...2018-08-03.pdf