Two way `ion-infinite-scroll` to prepend and append data (agenda style timeline)

when using the ion-infinite-scroll, the input property position can be set to either top or bottom. however i’m working on an agenda style interface where, depending on the direction the user scrolls, data is prepended at the beginning of the list (scrolling to appointments in the past) or appended at the end (scrolling appointments in the future).

unfortunately it is not possible to change the position dynamically by using a method e.g. <ion-infinite-scroll (ionInfinite)="doInfinite($event)" position="conditionalPosition()">, where the function conditionalPosition() would return either top or bottom.

are there any suggestions / workaround someone knows of?