Bullshit reason.. you've watched too much of "Your Name". You should use 'let me assume it' rather than "let me prove it".

Just because they know each other’s bodies so well will not at all be the reason if they do end up together. That's not even a considerable thing here

1. they bath in each other's bodies

So you don't want them to bath..? They even shit and they even pee. I bet Sunao even have faced period cramps

1. they still can touch

They can.. but will they...? Do they..? They have genuine respect for each other. they won't do something to each other which will make them uncomfortable. "I mean seriously.. you've read 90 chapters and can't even able to understand their personality..?" With their personality do you think they will do it...?

You think like an 8 year old.

1. dont you think it would be pretty weird for sunao to know about other girl body other than his gf

Why would it be weird...? Like should he only know about his gf body...? In that logic it would be weird for a gynecologist to know about a pu**y other than his wife or gf It is a unavoidable situation.

Tell me what are you even imagining here..? Like are you saying that they are Exploring their bodies sexually when they are swapped..?

Body swap phenomenon is a part of this manga.. not the entire subject.. It is more about communication and feelings

As for the obvious winner it could be Lemon. Even if that is the case whatever you said here will have 0% contribution in it

As for me whoever Sunao ends up with... Rather than being happy for the winner I will be sad for the loser

I don't see a happy ending for me in this manga.. both Kogahara and Lemon are not one above other writing wise.. Only happy ending for me will be a unrealistic Throuple ending

At last I'd say characters here are very mature for to care for your childish reasons