Hi Thomas, I am not familiar enough with Nei Gong and Jin and Qi are Chinese concepts that are linked to some specific Chinese Martial arts I do not fully understand.
Also, I cannot answer for the many Ryūha (Japanese schools) as among the one I have experienced, they all have different specific drills to develop internal qualities fit for their way of fighting, weapons etc. (Like the floating step, etc.).
To answer for Aunkai, there are a limited number of Tanren (exercises to forge the body) with many variations depending on what internal aspect we want to focus on and Kunren (pair training).
Below, 3 links with Sensei explaining tanren (this is only the tip of the iceberg and the internal part is not really addressed) but it can give you an idea of the solo (and very bitter) tanren we do.