Okay, so the reporter starts off on testing of the protomolecule instead of the disappearing ships... but then at the end of the last episode, a ship disappears! Why change that?! The intrigue over what was happening with the missing ships provided a greater intensity. In the case of the show, they clearly show the ship disappearing, where in the book, the character and ship kind of just vanish, making you wonder what exactly happened.
Bigger complaint, season four has absolutely no purpose for having happened at all. Book four is the exposition that life in the ring is possible and the consequences of people choosing the ring (including Mars) was going to be catastrophic for the Belters. This is the part of the plot where you need to have empathy for the Belters and understanding that Marcos is right, in the sense there is a substantial problem that the Belters need to overcome because they are now obsolete. The amalgamation of Pa and Drummer pushed this through as they were supposed to be taking from Earthers heading to the ring and giving to the belt. After all, there is a specific reason Marcos wants the Ring. This is all dropped making Marcos into a one-dimensional villain who at times looks like he knows what he is doing. He is portrayed as a meglomaniac with control issues, but isn't provided what all villains need to be great villains, half of a good argument!
All of that could have replaced the needless Avasarla's attempt to uncover the plot and then the UN Secretary impeachment which wasn't needed. The rocks should have been a surprise, but they just told you what was going to happen.
