I'm trying to create a VerticalScroller that remembers its position when the page is redrawn - I've tried

val scrollerPosition: ScrollerPosition = +memo { ScrollerPosition() }
VerticalScroller(scrollerPosition) {
  // etc.
}

but it scrollerPosition.value always seems to be 0px

You could store the ScrollerPosition in a ViewModel or somewhere else. I guess in the future compositions will be retained throughout configuration changes.