Is there a kabbalistic preference for the author of a sefer to create a title alluding from a posuk alluding to his name? If so, why?
In one of the introductions to קהלות יעקב, The Steipler references an old practice to weave gematria of one’s name into the title of his book.
In his case, קהלות is equal (541) to his second name ישראל. His first name being יעקב of קהלות יעקב.
I don't know if referring to it as a "kabbalistic preference" is an accurate idea.
Basically, the idea is that a book written by someone is their essence, so to speak. Think of it as the programming line code of who they are. It captures their mind.
Just like the Torah (the five books of Moshe) is the essence of G-d's will and the letters of the Torah are, according to the Zohar, G-d's name. This is why one of the explanations of cleaving to G-d means to learn Torah.
This concept also has interesting implications in regard resurrection of the dead and the returning of a persons soul to a reconstituted body.