Hi - so I found the solution to my problem with variable slide heights for ion-slides ui component.
<ion-content padding class="slider-zoom">
<ion-slides pager>
<ion-slide>// then adding ion-slide { overflow-y: auto } in scss helped!
<ion-card>[variable content]</ion-card>
</ion-slide>
... more slides
</ion-slides>
</ion-content>