Speculation time! Now that I don't have to spoiler bar everything.
Koyomi is not satisfied with the current ending where the MC ends up choosing her lover's identity. The lover very much mirrors Yuu's relationship with Touko. This possibly means that this manga won't just end with Touko going along with the self she has around Yuu and that it's not exactly THE true identity for Touko.
Up until now, I've only considered Touko's identity crisis as being reflected in her relationships with Sayaka and Yuu, with Sayaka as someone who supports Touko's ideal self and Yuu as someone who supports Touko's more honest self. Going along with this thinking, an ending where Touko choosing to be who she is around Yuu was what I initially thought to be the obvious outcome for this series. However, this chapter with its more extensive look on the play adds another interesting layer to Touko's identity crisis that I've yet to consider & that is her relationship with her family. One of the factors that cause Touko to choose to live her sister's life in the first place is what her relatives told her upon the death of her sister: "Be like your sister." As seen in the last chapter, there's also a bit of tension between Touko and her parents. They've caught on to Touko's intention of carrying out the life of her sister and are actually worried about her. However, Touko with her inability to understand/accept others' love for her, puts a distance between her and her parents as she refuses to heed their advice.
Taking into consideration all of the relationships involved in the play and in Touko's life, we see friendship, romance, and family. Three very basic interpersonal relationships in any person's life. Touko has all three, except they are all shallow. Shallow because Touko herself refuses to accept and rely on the love and support that these three relationships can offer her since she sees love as a shackle. So, at the heart of Touko's identity crisis not only lies "who will she become?" but also "what will become of her relationships?" Because of this, I think it's smart to have Koyomi question the current ending to the play. Touko's identity crisis is much less black and white than I previously thought. And so, based on what the story has revealed thus far, my new prediction is that the play will end with the MC rebuilding her relationships from 0 while finding her identity in the process, rather than picking any 1 out of the 3. For Touko, this will be her rebirth.