There have also been a number of discussions that address the question of 'are Jhanas necessary, like this one. Please Note that if you want to discuss more on that topic please do it on the existing thread and not on this thread (tidy housekeeping)
The way EBTs themselves say how to determine if something is authentic is to see if it fits into the Dhamma and trainings for monks. I see nothing in this EBT that isn’t found elsewhere. It’s just about the DO!
You should read it, if you haven’t already. For me parallels help distinguish what was written hundreds of years later, after the teachings were brought to China.