In fact, Jacob was quite concerned about the Si family. He thought highly of them, and the only ones who could meditate were in the 2 branches of the Si family. If he had a good relationship with Alessia, she would be of great use in the future.
There were very few people in the world who knew about the Si family. They didn't know that the Si family members had to use a tool to channel their powers. This time, Alessia had gathered enough materials. As long as the power battle was successful, the Si family could do whatever they wanted in the future.
However, there were still some minor problems within the Si family. Jacob needed to help solve them one by one. However, those were not big issues. For Jacob, they were just a piece of cake.
If he got the support of the Si family because of it, Jacob felt that it would be a very good deal.