From my understanding you don’t have to keep doing pe forever. What you have to do is what is called cementing your gains… for example, you gain to 8 inches in length over a 12 month period. What you would need to do is keep up a maintenance routine for 2 or 3 months to cement your gains. Your maintenance routine would consist of a less intense and less frequent routine basically designed to stabalize the gains you’ve made. My personal belief is that if you want a solid 8 inches permanently you will need to gain to 8.1 or 8.2 then cement your gains and if you stop alltogether you will probably loose .1 or .2
Most people that start PE and make those kind of gains though probably would develop the habit of PE and would just continue doing it lightly there whole life just to maintain penis health.