In what case is the pattern of modification variability manifested more clearly, with a small or large amount of data?

With more data.
Modification variability is non-hereditary. This means that it entirely depends only on external factors and the living conditions of the organism’s environment. The more data a particular environment has, the more powerful it will have on the body. Due to this, the creature will have to adapt to the new conditions. And all the modifications will appear very clearly.