I just grabbed my most upvoted comments and “put them behind the paywall”.
Of course there is no paywall, but you just get to read the first few words that were there and then I edited in a message saying:

This used to be a full comment, you can find more resources in the link bellow since I have moved to kbin and reddit doesn’t deserve my content! Bye reddit, you won’t be missed!
For more [subject] advice, find me on https://kbin.social/m/[subject]

Bonus points if I could cut the comment out at the exact time it was about to become useful “Whats actually going on here is that…”

I did that for fresh comments going back to 4 months and most upvoted comments going back until I reached the ones with 20 upvotes. It was manual, I was waiting for something to process in my work computer.