It looked to me like the exercise schedule recommended by Xeno was not especially intense. In fact I found it reminiscent of the newbie routine; start with 200 Jelqs and increasing at a factor of 1.1. After a two month break this is probably more than enough to reach fatigue, but I don’t think that you risk any sort of injury as long as you are careful.
This is not a recommended routine. It is an example, of an exercise familiar to all, from the newbie routine used to explain the increase in workload from one workout to the next. Somewhere in there I remember reading Xeno saying Jelquing itself would never cause the type of inflammation we are after.