We determined the characteristics of the hardness components based on the 157 test tasks of the FS-Mol benchmark. Multiple modeling setups and parameters were explored to determine the method's sensitivity. These will be discussed in the subsequent sections of this work. Here, we begin our analysis using one defined modeling setup: representation of the small molecules with GIN-supervised infomax; representation of the proteins with ESM2-t33-650M; consideration of the ten nearest source tasks (accounting for approximately 0.2% of the source tasks) for calculating hardness from distance matrices. Normalization was applied to have all values fall within the range of 0.0 to 1.0. This default modeling setup is representative of all explored setups, and, as we will see later, the conclusions drawn from any explored modeling setups are consistent.