Nine months later, I can now substantiate my claim. A search on this platform reveals that the third place globally, among authors with the most indexed books in my field, is held by various authors, each with a total of 12 indexed books. However, it is irrelevant to know their identities or production dynamics because even if, by some unlikely chance, they started producing three books per year, they would still be unable to break the record by 2029, the year of my retirement.
The only real danger lies in the professor (at a university in Australia) who occupies 2nd place in the world, holder of an impressive Scopus h-index=94, and who has 20 indexed books. It turns out, however, that he needed 20 years to produce them, so it will not be now, at almost 70 years of age, that he will start producing at a rate 300% greater than what he has produced in the last two decades. But even if by some miracle this improbable thing were to happen, it wouldn't be possible to break my record, for the simple reason that I haven't stopped yet, nor will I stop producing anytime soon.
