I might actually make my own subreddit for this sort of thing, unless that already exists somewhere? A subreddit dedicated to crossposting useful responses to old, forgotten posts otherwise doomed to obscurity
It makes me equally happy and sad to find a years old reddit post with <10 upvotes and maybe two or three comments asking a question that I have an answer for. I will always respond in the hopes that *someone* will see it and get the info they need