Wow, first time in a while that I've come across a homophobic "psycho lesbian" archetype in the wild like this. I judge the author hard for how two dimensionally awful they wrote Bko. She's a character straight (heh) out of one of those cheap paperback lesbian-sploitation erotic novels from the 1970s. A good wholesome girl gets baited and/or coerced into getting trapped by an evil psycho lesbian and it's saved by a nice wholesome Christian man who's definitely not abusive or controlling, unlike those mean lesbians! This author has of course innovated on this formula by replacing the hero with a legal loli. ...yay, I guess.
You are working really hard to twist this into something that it is not. The "psycho lesbian" is a secondary character whose main purpose is to bring into focus Big Imari's insecurities and she is given sufficient characterisation to accomplish this. She is a possessive, jealous abuser who preys upon her love interest's social anxiety, and is a fairly realistic depiction of how such people operate, by isolating and controlling their object of obsession. This is only "homophobic" if you think women are incapable of such things. The work is clearly tagged with Abuse
and there is no Het
tag, so it should have been obvious that the abuser would be a woman. The author could have added more characterisation to Rika, but to what end? This was not a story about her. For the role she had in this, she was sufficiently fleshed out.
The "good wholesome girl" is a bundle of social anxiety whose first instinct when things get tough is to run away in order not to cause trouble for anyone, and the "nice wholesome Christian man" (the levels of projection are off the charts here) is a messed up woman who resorts to self-harm in order to supress negative feelings. This is a story of two damaged individuals finding love and in the process helping one another with their respective issues. None of it fits into your cartoonish parody of a description. "Legal loli" is also laughable. Small Imari is short and likes cute clothes, which is not a "loli". Neither her face nor her facial expressions are in any way drawn to look more childish in comparison to other characters. Again, you are obviously having some sort of a knee-jerk reaction here and are projecting hard.
"This author has of course innovated on this formula by" not actually doing anything remotely similar to said formula. Your entire premise falls apart when one considers that all three characters here are women, but by all means, let us try to force a square peg into a round hole.
As a side note, the woman Big Imari was in love with in her old company was also somewhat similar to Small Imari, in that she was short and had light hair. Big Imari clearly has a weakness for shorter women~