She sure got energy, and she even found a solution she’s fine with for now. She’s so loveable I don’t care about the childhood friend anymore.
Personally, while I like this development, I personally think that the ideal outcome would be a polyamorous relationship between Asumi, Nanao and Mai. Perhaps Asumi can start by bringing Nanao along on some of her brothelly adventures and the two of them double-team Mai. If that isn't possible then like you I much prefer Nanao as she's fucking sincere and totally adorable.
Some commenters have mentioned that Nanao has permanently friend zoned herself. I really disagree with that. It's clear that Asumi is sexually attracted to Nanao and has some feelings of affection for her regardless of the complication that reconnecting with Mai presents to her current relationship with Nanao. I happen to think that at the very least, Nanao is definitely in the running to win Asumi's mind and love.
Oh, yeah. One final point. Asumi did rather enthusiastically decide to have sex with Nanao, so at the very least, there is definitely a foundation for them to build a lasting romantic relationship. Both girls are generally friendly, they share common interests and they find each other sexually attractive. Mai is already on the back foot here, regardless of how Asumi's desire to still reconnect with Mai and sort out her feelings about her.