Ooh that conversation is so good !!! Go off Ah Duo, tell him what you really think !!.
The emperor and Ah Duo are essentially a foil to jinmao in very obvious ways because Ah Duo and Maomao are definitely foil to each other, as Maomao refused Ah Duo's offer to flee, an offer Ah Duo might have taken if it was offered by someone at the begining of the the forced romantic relationship between her and Yoh.
Also, Jinshi is definitely a foil to his father here with them being in very similar circumstances but making incredibly different choices, He will definitely let Maomao go if that's what she wants. Actually, he already did. it was misguided because they weren't good communicators (they are getting better) when he let her go back to the brothel as early as book 1, thinking that's what she wanted. He is now actively trying to not touch in any way because he doesn't want to trap her and he would never order her to sleep with him the way the emperor did (which is very fucked up, of course she resent him for this)...
But also, Jinshi is also a direct parallel to Ah Duo because he also wants to get out of the palace. The emperor, as long as he is alive owns both of theirs life (and literally everyone under including Maomao) and Ah Duo is trying to get him out of the situation because he would be a) extremely unhappy b) extremely dead sooner than he ought to be by using herself as a sacrifice.
(I'm sat with the popcorn during this entire conversation, it's so good).