If you want to make movie or TV series of a semi-autobiographical novel, be careful how you use your own background research. It is, after all, still a novel, and the author has made the deliberate choice where to write fiction and where to include events and experiences and people from their own life.
I see a trend in more recent adaptations, for instance the newest adaptations of Little Women and All Creatures Great and Small, but also many others, to blend in historical facts that don’t actually fit in with the author’s own blend of fact and fiction, and thus loses its actual impact.
If you want Jo March, whose personality is based on Louisa May Alcott herself, to be Louisa, she will be an alien to the world she created, because Little Women is still a novel, and because all other characters still exist in their fictionalised form. Just because she Ms Alcott made the decision to weave in her own happy and unspeakably unhappy memories into her stories, does not mean that you can equate her with a fictional character. Just because Jo is very much like Louisa, she is still Jo, as written by Louisa.
If you want to express that Siegfried Farnon, like Donald Sinclair, was already a widower in the beginning of the story, a fact Alf Wight (James Herriot) and the writers of other adaptations left out out of discretion, then you can do it, but if you cast him as a man in his 50s (which is actually a very good thing, because he felt and appeared so much older than he was) and make him a widower of four years, for everyone to know, then the fact that he lost his wife at the age of 24, and began an entirely new life afterwards, will get lost, and with it the whole inclusion will lose its “point” beyond “look, we dug up some angsty trivia!”
You wouldn’t make Amy March marry a younger man in her late 30s, rather than Laurie. And you wouldn’t make Helen Alderson a town-bred secretary which James’ parents didn’t approve of. Because authors know what they include from their real lives, and what they make up.
Or take the 1999 Mansfield Park. If you want to adapt a novel, and find its heroine to be a bore, you might rather choose a different novel, rather than turn her into Jane Austen. Even though Jane Austen drew on some personal experiences, it does not mean that Fanny is Jane, or that Fanny is so unsuitable a protagonist that she has to be made Jane.
Because a semi-autobiographical novel (or a fictionalised memoir) is not an autobiography.
(Note, please: I do not mean that these films are bad because of this, or anything of that sort. They are just good examples of what I mean, and whether I like them or not or whether they are otherwise good or bad is in no relation to this. And the first two are also very recent, and a good example of that current trend. The third, however, shows a different way of doing this, which is also not a good idea.)
And there are many, many other examples, but I think you see my point. If an author includes things from their life, then they know why and what and how, and it is only up to them. Especially if the finished work is, after all, a work of fiction.
Learning about some more background is lovely, being really invested in such a work is a brilliant thing, but if you want to include that knowledge in an adaptation you must be really, really careful.
You might include some allusions, or some sort of little nod to this or that. Some detail that those who know will recognise and appreciate. That sort of thing is lovely. And there’s a lot of possibilities there, one can hide a good deal of Easter eggs in a movie, as long as one stays subtle and respectful, without trying to re-invent the original work. A little comment here, a design choice there, and people can really enjoy it.
But crude info dumping, random blurts of this and that to cause angst or drama, pseudo-intellectual blends of fact and fiction that subvert the authors’ intention, or the inclusion of intimate details that the author (or other involved persons) never wanted to be included to begin with, do not improve your adaptation. It’s just insensitive, pretentious, and in many cases off the mark.