My main takeaways from the long long correspondence between Elston and Evans:
Confirms the role of the Chester consultants in choosing cases for him to examine. Private Eye have something on that this week too - print only for now.
Fairly sloppy on details of the cases he discusses, but this is private correspondence so even where he's evasive or omits things, not sure where you go from there.
Undertakes a statistical study despite patently not having enough information to confirm its significance - this was reported in the Telegraph back in November and deservedly sank like a stone. A reasonable sidenote is to ask why Chester Police are sharing relevant files with him outside his now concluded duties to the investigation, but can't blame him for that.
Effectively denies that the difference Shoo Lee has cited between venous and arterial embolism exists, but his grounds for this claim aren't really given.
I don't think the correspondence tells us much new about Evans. It certainly confirms problems with the police investigation, and I find it interesting from that angle.