CHYSA has confirmed that August, the best friend, is a romance option! He is not listed on the Itch.io page, but he is listed on the Steam page as one. Also your taste in characters are great as mine is the same.
In terms of NSFW scenes, all male characters are verse but may lean to specific positions; some are verse/tops or verse/bottoms. So, the MC can be top or bottom, but he may lean towards a position with particular characters.
No worries, the question about August being romanceable is a hot topic, lol. I saw it answered here on Itch.io! The first time CHYSA 100% confirmed it here was seven months ago in the comments. You can see it if you scroll down!
P.S.: I agree; I am obsessed with all the characters, but August is my ride-or-die.