I don't know if Irma perceives it, but I did consider and worry about the implications of making both the lovers she'd be reluctant to give up male while writing. But I felt I had to give the nod to canon with Argus, and the story with Filius kind of ran away with me, and (as usual) deadline pressure finally just forced me to go with what I had.
For what it's worth, I do think Irma underestimates Min's fondness for her. It's entirely possible that if it weren't for Filius, she'd be invited to join the sessions with Rolanda more frequently. But Min is also quite fond of Filius in a different fashion, so she tries not to create unnecessary complications.
Anyway, thank you so much for the lovely (and perceptive) comment!