Yeah, the story is linear, staying true to the game title 'Beauty (MC) and the Thug (Hunter).' What is left is work on kinks in a sandbox way. But people have been asking for a lesbian only route for quite some time, so maybe it will be implemented in the next update.
As
JNev stated, there already a lesbian route, I'm on this path.
But as you write, the title of the game being "Beauty and the Thug", the thug aka Hunter will be still here.
Some players could be annoyed by that, thinking why I still see him if I reject him.
But apart that he is a main part of the game, it make sens for this character to come back even if Lisa reject him. It's a thug, he is rather handsome, and he is probably not used to women rejecting him.
So it make sens that he won't take a first "no" for a no. Probably thinking "WTF?! How this girl could reject me? It can't be. She will succumb to me". As a result, he will be insistent to have other dates with Lisa.
But you can totally friendzone him. He will be still here, but as a friend, helping Lisa. And I suspect Lisa action towards him could change him in the future to become a better person.