I'd personally prefer it if you kept it on ao3 but I do see your point... I mainly am on mobile so tumblr and fanfiction are harder to acess for me so ao3 was a real blessing... but it's your story and as a minor i have some of the problems u describe, i can deal with some porn popping up on searches or suprise porn in stories but there is no way of stopping some of the problematic™ stuff that comes up and it bothers me enough i stick to bookmarks and recs mostly and avoid tags
Like I said, fanfiction.net’s app is wonderful, though you have to save the fic to the app’s library to get it to update on your phone iirc? but it’s got so many options and reading is so much easier on there, the download options saved my life when I was off in no internet land.
Tumblr fic is…pseudo-accessible. You can get notifications for the blog and such, so I could make a blog strictly for updates… I’ll look into it.