One thing that might be helpful, and this is largely speculation on my part as I have not experimented with it, is something called periodization. Essentially periodization is switching between high volume/low intensity sets and low volume/high intensity sets.
Periodization can word inter-session and intra-session. By this I mean that one can periodize within the same session or through different ones over longer periods of time.
An example of this choice:
One could begin their workout with a light set for 20 minutes, followed by two medium sets for 10 minutes each, followed by a heavy set for 5 minutes, followed by medium again, and finish with another light set for 20 mins. All of this being done in the same workout.
Alternatively, one could interchange over longer periods. Say, have three sessions a day: high volume in the morning, heavy weight in the afternoon, then medium at night.
Or over even longer periods: high volume low weight for one or two months, followed by one week of heavy weight, then return to high volume, etc.
That said, I would always recommend spending not as much volume (read as: time under stress) using heavy weights due to the general opinion that heavy weights can quickly build resistance and increase inelasticity in parts of the penis.
The best method I believe for periodizing, therefore, would be over shorter periods of time. A week at most, but preferably all within one workout. That way, you are essentially hanging low weight and high volume (which I believe to be the preferable of the two because it does not fortify inelasticity as readily as heavy weights) while still augmenting your workouts with the trauma that is associated with heavier weights.
The theory is that this allows for more trauma without your body getting used to it. Too much time under heavy weights builds resistance, but no heavy weight at all forfeits the beneficial trauma it can provide.
2020: 7.1 BPEL, 6.125 EG (base)