I havent had a lot of experience of modern engine hg replacement.
but over the years i have done just a few.
Of course there are loads of different types, but I have rarely done one more than once.
there used to be a time when you had to take yer new motor in to have the head tightend down.
Someone may correct me, but I dont think that this applies anymore.
Also, whenever I'm doin a hg, I am quite fussy about sticking to the set pattern regarding torqin down.
Which includes numerous repititions of the correct pattern.
There are also the cheaper bendy bar torque wrenches, which I wonder if they are up to the job, though i have used em.
Also, I have found that even with an expensive clicky 1, there can be quite a difference in setting, depending on how quick or slowly you use it.
From what I have seen of most hg's, they aint changed much.
So I am thinkin why does there seem to be so many probs with em.
It aint just LR stuff surely.
Maybe all the hgf is perhaps down to original installation+ not re-torqued,and/or method of replacement in later life.
Not just, its a flander/RR etc, thats what they do.
just my two penneth on the subject. maybe only worth 1p!!