I'm really not sure about this conceptually; there's definitely a lot of pretty fun ideas in here but it feels…too much like it doesn't quite go anywhere interesting to work?
Like, it's very much an exploration style log and there's some cool elements, but it doesn't really…end with like, a big discovery or anything so much as just a quiet 'yeah we're just gonna pretend to be in the stone age still' (which, surely should be a trivial illusion to see through if the exploration team was on the ship? Like, guns and radios and stuff are very obviously not stone age tech and also very obvious if you have any kind of internal monitoring systems at all; and even if the probe didn't, surely it'd have some kind of external ones that'd detect like, tv and radio broadcasts and stuff?)
More to the point, if the entire point of the probe is to suppress humanity, but the probe was like, always here, why did it not like, do it's job very well? If it's so bad at it's job, why do the Foundation worry enough to create this big, complex illusion?
TL;DR: this really needs a stronger ending. I think the journey to get there could definitely be fun but I don't think it wraps up in a satisfying way.