Primo is available in both oral and injectable form, but it has not proven to be a successful mass building drug when taken orally because the liver usually destroys any traces of Methenolone Acetate that is ingested through the mouth. Similar to Anavar, it is mild and contains less of those steroid properties which leads to water retention or acne or any other side effects that are related to estrogen. This makes Primo a very successful drug amongst those who become easily prone to side-effects like skin problems and digestive issues.
For the off-season athlete there is no anabolic steroid more important or beneficial than testosterone. High levels of testosterone will promote significant increases in lean muscle mass and strength. This is assuming that the individual is consuming adequate calories. Compounds like Testosterone Propionate are not magical, you will still need to feed your body enough calories. During an off-season period of growth, this means total caloric intake will need to be slightly above maintenance. This will, unfortunately, promote body fat gain. However, the key to a successful off-season is gaining lean tissue while minimizing body fat gain to the fullest extent possible. By supplementing with Testosterone Propionate you will be able to achieve this more efficiently. High testosterone levels will promote a stronger metabolic rate. This is not a license to eat like there’s no end in sight, but you should be able to make better use of your calories.
I don’t believe that the body can grow strong due to tendon/CNS adaptations as you keep asserting. That may work for a few weeks when you begin a new exercise & improve motor skills and structurally adapt, but it will not last long. You will never get strong in the long run if your muscles are not also growing. But I think many people have vastly overestimated the impact on your appearance that gaining muscle actually has. Gaining 5 lbs of fat will make you appear much sloppier, but gaining 5 lbs of lean muscle will not make that much visual difference while wearing clothes