Position of animated element in scroll into view interaction

Hello everyone!
In the midst of creating a scroll into view interaction, where pictures are meant to reach their largest width when their centre reaches the centre of the screen (speaking in vertical terms).
Now, because the keyframe field in the animation panel only accepts numerical values in % (and not keywords such as ‘centre’), the spot where the largest width is reached can’t possibly be the screen vertical centre every time, ’cause this will vary in percentage position every time depending on screen resolution!
Is this a fair conclusion or is there a way to achieve what I want that I’m not aware of?
Thank you everyone, if you could shed a light on me about this it would be awesome! (edited)

Here is my public share link: https://preview.webflow.com/preview/busto-and-sun?utm_medium=preview_link&utm_source=d[…]n&preview=651f73c57b1e7c62060c1f40de09faf5&workflow=preview
(how to access public share link)