The PowerDeleteSuit fork I used had no problems editing 2y old comments. I did a websearch for my username and chose a custom time for the results, which I set to between one day before I created my account and two weeks later. The oldest comment I found by doing so is from ten days after I created my account, and it is edited like I instructed the script to do. Wasn’t a popular comment either, with just 3 upvotes. I think I’m in the clear!