I'm wondering why there is a processing limit of around 200 items per feed. I've worked on code that processed hundreds of thousands of items from CJ feeds but it wasn't in the WordPress environment. I've tried using the set_time_limit(0) function of PHP but it made no noticeable difference. It seems to be a timeout issue, though. If you upload a large feed, the script stops after X number of items and doesn't display the upload count.
Since many CJ feeds have hundreds or thousands of items, it would be good to solve the 200-item limit somehow. I'd be willing to help if I knew where the problem is.