What is your opinion on the lengthy Ruqyah Shar'iyyah widely available online by one of the reciters, and is it advisable to listen to it in its entirety at once, or in intermittent sessions?

Listening to legal ruqyah is good and beneficial, Allah willing, whether all at once or intermittently. However, it is recommended that a person perform ruqyah on themselves, or have a trustworthy raqi recite it directly over them.