Not much (thankfully!) in the AAIB bulletin for April as no flying - once Commercial and GA returns to normal levels the monthly bulletins will be the size of the yellow pages!
Actual AAIB article for this one -
https://www.gov.uk/aaib-reports/aaib...g-21-july-2020.
"Subsequent use of the actual takeoff weight for performance calculations showed that all departure airspeeds should have been one knot greater than those used on the incident flight, and the thrust required should have been 88.9% N1 compared to the 88.3% N1 set on the incident flight."