Personally, I’m a fan of the milk drinking scene - for me it’s part of Luke demonstrating the Force (the nature of it; in the cycle of life and nurture - along with the fishing)
I agree with this, which I why I didn’t want to cut the whole scene. Luke’s milking the alien for me is enough to suggest his connection with nature and the force. The shot of Luke actually drinking it with the scornful look on his face (as if he was deliberately trying making Rey uncomfortable) felt a little too strong to me. Rey was already uncomfortable, so, for me, the purpose of the scene is already achieved without having Luke rub it in her face.
I took Luke’s scowl itself ss a ‘much to learn you have’ / ‘unlearn what you have learned’ type message - the realisation that he is now giving those lessons to someone young, naive yet willing… as once Yoda gave him - though you’re right, it is quite a strong look from him to that already uncomfortable Rey.
A difficult choice to decide / cut - though you’ve given yourself some quality possibilities…