Faction Paradox was an interesting concept. Be aware that some of the Eighth Doctor BBC books are a real slog to get through (Interference comes to mind - there just isn’t enough plot for it to be two books). The main thing I didn’t like about the wilderness years books (Virgin & BBC) was that they were distinctly more adult than the show, which I found jarring.
I do wonder what we would have gotten had Moffat left with Smith as he originally wanted. From what I heard, it sounded like he was stuck in the same situation JNT was in the mid 80s - if he wanted the show to continue, he had to run it. Unfortunately in both cases this corresponded to a decline in the show’s quality (Colin Baker really shines in his Big Finish audios, but a lot of his TV episodes are terrible due to the writing; Sylvester McCoy fared slightly better, but still had stories like “The Happiness Patrol”).
I haven’t actually seen any of the Whittaker episodes apart from part of “The Power of the Doctor” (which my wife watched in its entirety and thought it came across as bad fanfic), but after I heard about the whole Timeless Child arc (which apparently Chibnall came up with as a kid watching the Seventh Doctor), I was not impressed. It felt like there was no respect for the show or its continuity. The Whittaker era might have been okay by itself, but as the part of the larger universe, it really grates on me.
This is one case where I think Windows is appropriately designed for its target audience.