Voyager has a setting for “No subscribed in All/Local” that does this. It’s better on than off, obviously, but it doesn’t turn All or Local into some kind of goldmine.
I get the sense that, unless you’re willing to do it yourself, feature requests for Lemmy don’t have much chance of being realised.
No settings page (as far as I’m aware), but you can use the API to get everything (posts, comments, etc):
step 1: get login token -
curl --request POST \ --url https://lemmy.ml/api/v3/user/login \ --header 'accept: application/json' \ --header 'content-type: application/json' \ --data ' { "username_or_email": "2br02b", "password": "YOUR-PASSWORD" } '
step 2: use login token (big long string starting with ‘ey’) to get data -
curl --request GET \ --url 'https://lemmy.ml/api/v3/user?username=2br02b&page=1' \ --header 'accept: application/json' \ --header 'authorization: Bearer YOUR-JWT'
Increment page number until you have everything. source: https://lemmy.readme.io/reference/get_user