This review is based of my impression till chapter 102. It's like 3.5 to 4 in the quality of story for me overall.
First of all the Mc here is 8man but if you have read other COTE ff with hikigaya as Mc, specially the previous fanfic which was tld by this author or Cote hikigaya in classroom of the elite, this hikigaya in comparison is a complete joke but if you haven't read those two then you will be ok with how 8man handles things in this one. Frankly this one is more in comedy centric and completely useless monologs then actual plot. Also reminding of plot, I am at chapter 102 and barely island arc has started so yes the plot is stupidly slow, Mc here cares about making class D reach class A and now his class is in Class C. The reason given is he made a deal with Sae sensei for 30mil cash if he reaches class A though good thing is he doesn't need to maintain that class after reaching it once. but due to deal, you can just kiss goodbye to the loner self centered hikigaya if you were expecting one, he will priorities Class as a whole due to very nature of the contract. He also doesn't have a good insight to see through peoples disguise so don't expect that either. and for romance? there isn't any here till I read, and harem? that tag looks like a lie for the most part but can change since I saw someone said his patreon has 200 chaps but meh.
The famous chess spot which most Mc uses to make big profit on private points was skipped. Power of contracts is not used by Mc for the most part so if you are expecting Mc to 5head play other classes to extort point, just give up. Mc is said to be smart and things of that nature by arisu but when you read his inner monologs, you will be like what is she smoking to call him smart but don't get it wrong, this 8man is actually much closer to oregairu one then others but that is also a demerit for cote setting if you have certain perception of how an Mc would act in fanfics like these so it's upto readers taste.
there are a lot of author inserts through out the story and breaking the 4th wall trope done in-between author to hikigaya, shizune, kushida and hiyori. there is also hidden jabs to authors previous tld fanfic with how kushida end up, hiyori knowing hikigaya when she hasn't even met him at that point in the story and Yamaguchi with hm dying by yakuza.
For oregairu crossover, this one has mentions of komachi being a good sister who cares for him and the first girl who 8man had confessed previously and the sensei who is actually also friends with Sae sensei and actually has a company in partnership and is also the reason why Sae can afford to give 8man, 30mil for class A promotion. Author also has said that yukishonita and iroha will come in year 2 but given the pace of the pace of the story, it will take ages.
Now going back to Cote plot, some key things were changed via Mc interactions. one being Class D didn't hit 0 class point in the code of conduct test due to 8man destroying a camera so the class points were revealed to everyone which ended up stopping Class D being a complete trash 0 pointers. Class C making the deliberation about Sudo which made Class C end up loosing 400 class points coz of hikigaya and Airi were present during that time and won the case easily. Kushida hitting the railing and it was 8man who find her and also the grope happened but 8man reverse played her and making her one of his tools and so on. This story explored way too much mundane stuff before even the first class test happened, it was so slow and I actually don't even remember most of the stuff either.
Overall a pretty mid fanfic but could be good for people who doesn't have many preconceptions for characters so this was pretty yikes for someone like me but maybe will be good for others. With my personal bias I would give this 3.5 to 3.7 but without biases it's a 4. (in my scaling 4 is usually average story and 5 is story I would recommend to people)
