For me a plateau is when you have zero gains after 2 months of dedicated PE.
You can overcome plateaus by making CHANGES.
If you have a certain routine with a certain intensity, you can change the intensity at the beginning, always monitoring well your PIs.
If the maximum intensity level is reached, then you can change the routine, for example if you are after length, you can go from stretches to hanging or small-diameter tube pumping.
Making a circle with all lengthening methods and managed to hit a plateau at each an every one of them, is something that can take years. Then, managing to be constantly on a plateau, that means, to have hit a plateau at all methods and not being able to gain with a method change is something that can take a lifetime. If so, yes, a decon break could be useful, but we are talking for more than 10 years of PE, considering that a plateau is really hard to reach if you are making changes to your routines.
For example, if you start hanging, you can only hang SO or BTC. If that stops working, then you switch to OTS or v-hanging (hanging over a bar for maximum tunica expansion).
It is really hard to hit a plateau, and most people hit those because they over-train themselves, not giving the time to their body to take the full benefit of an exercise. Just because someone starts hanging, it doesn’t mean that he should hang all possible ways withing the first couple of months.
With this method, gains are slower but more steady and consistent. Since PE is something that I will be doing for a lifetime, I am not in a rush, I will take all benefits from each exercise.
My two cents.