Having read the first 4 volumes (1,2,3,4.1 and 4.2) so far, this is meant as a partial review only. Also, I'm not really sure, if I will be continuing to read – and this is not entirely related to the work at question here. So trying to write out my thoughts up until this point whilst my memory is fresh seemed a good way to do this work justice. Whilst I have admittedly only recently (2020) started with reading Light Novels and completed 2,5 so far – Mushoku Tensei; Shield Hero; Slave Harem in a Labyrinth – I sure was pumped at the beginning to readsomething people praised as "as good as if not better than" Mushoku Tensei, which still lives rent-free in my mind to this day.

The novel angle of this LN are tabletop RPGs (TRPGs for short), the important aspects of which get explained throughout the books via little info texts here and there, which is fine at the beginning, but surely gets boring after a while since the plot implements very little of said genre except for the mostly well written "alternative timelines" at the end of the volumes. These short stories try to shine light on the question of "what if the plot took that turn here?", which makes for good meta-storytelling and further expansion on (side-) characters. Also it allows for delving into philosophical questions that normally wouldnt have occured otherwise.

PRO: The characters are really well written and their at times complex inner thought processes and relationship dynamics get enough space to see them come to life and at times even to be relatable. The world building is really good and one can see the different elements come together. The many races of this fantasy world have distinct features and one is intrigued to read more about them to find out, how they interact with each other. The only exception would be the "immortal" races, of which at least one specifically seems a tad too overpowered to be fitting in the big equation of the world, but that can be ignored.

CON: Although the premise of the story is a so-called "munchkin", a player that tries to maximize his/her chances of survival whilst doing the minimal of investment in skills of his character build, we only get an initial glimpse of MC's blessing (spending experience points into said skills) at the beginning, but his build gets practically ignored after the 2nd volume and no real information is offered to understand his options, which make every new skill he invests in later on only more annoying since they seem more of an afterthought of the author to overcome plot holes rather than being genuine build mechanics a fan of RPGs would enjoy to read more about.

Summary: The first two volumes of "Min-Maxing my TRPG-Build in Another World" have a good start with all the Isekai elements I came to love about. A relatable MC starting out small, albeit with a blessing, working their way up the ladder of the intricate fantasy world, whilst said world is taking shape and immerses us, the readers.
However the 3rd and both parts of the 4th volume manage to lose me many times over during the read because of how boring or hastened developments seem at times, whilst accomplishments of the MC, and most importantly, the development of his build, which is basically in the title of the work, seem either to be forgotten entirely or at best remembered when certain plot elements seem to be in need of development, which is sad.

I am gonna read vol. 5 to decide whether the series is really worth it for me. So far, I would like to give this work an 8/10, but unfortunately it's "just" 7/10 for me. Still enjoyable, but would have difficulties to recommend in general.