One could just mass edit all their comments to contain some garbage with power delete suite. Of course they would have to hurry, as that relies on the reddit api for making the edits.
PowerDeleteSuite only gets the comments shown in your profile, which is limited to 1000 comments in each list: New, Top, Hot & Controversial. You need to do a data request which contains CSV files with links to all your comments, then you can feed that into something like shreddit, in order to get everything.
I'm thinking, instead of mass deleting/mass editing, which would be easily detectable and reversed, manually editing high value comments like tech support or consumer advice.
You don't want to delete your account until you are absolutely certain that your content will remain permanently deleted, as it appears that they are restoring deleted content.
This... My worry is that they will revert my data AFTER the api calls. I'm not keen on deleting thousands of comments by hand. Remember that after the API changes all those tools will become unavailable.
i got my account banned and then i kept sending harassing messages via appeals. the last one was "i hope you have to suck dick for food when reddit goes public and the stock price drops" and next thing i know my permanent ban was removed.
One downside is that you have no control over your content when banned and using new reddit. If you load your profile in new reddit, it shows nothing, regardless of whether you're logged in.
Right now you can go into old reddit and still edit/delete your comments. However it's likely that reddit will kill old reddit on 1 July, if not before long after. After that it will be very difficult for banned users to control their content.