It certainly can be a challenge to find a good place for review scores in Japan that's sure. The uncertainty of Japanese gaming magazine scores and their question of legitimicy is an issue that sadly will never get a good answer for what's going on behind the scenes. Not to mention the frustration of Japanese user reviews too since many times those reviews are also questionable thanks to the practice of users just loading sites like amazon with the lowest reviews just to complain about some of the smallest complaints ever, or to complain about a situation with a release (for example the large number of negative PSVR reviews online at stores because of the lack of stock and scalping issues).
In the end, best reviews tend to be online through videos and social media and such more and more these days. Personally though I just go with my gut on games and that works well too. And weirdly, i end of agreeing almost always with famitsu scores. Except demons souls, that score was crazy. But yeah dengeki PlayStation does have some interesting reviews for people to check out if they are interested.