IMO if you write "at length" explaining something, copy that to your own blog or at the very least a markdown file on your own computer. Don't rely on a 3rd party site for archival.
I usually save things (not just Reddit comments, also HN etc.), generally speaking the bar of what I publish on my site is higher than what I may write in a comment. Sometimes I get around to polishing stuff, sometimes not. Other times it's just too specific to really publish on my site.
Finding stuff in the chronological list takes forever.
And this is where you find your own posts: https://www.reddit.com/user/SaveVideo/posts/
And comments: https://www.reddit.com/user/SaveVideo/comments/
Searching is crap, but it's Reddit so no news there =)