Make a feature so when you select an object you can click simplify and it reduces the node count, removing the old nodes and modifying the cudvature of the remaing ones to maintain the original shape.
The Vectornator team obviously has a time machine in their basement, as the feature is now already present (with perhaps some limitations). 
Recreates the current shape with fewer nodes, doesn’t necessarily preserve existing node placement.
On an iPad, select the path to be simplified, go to the Path tab in the Inspector panel, and click on the Delete Nodes button. Note: if you delete too many nodes eventually the path might change shape when there are insufficient nodes to maintain the original shape.
Huh. 
In the manual, it’s labeled Delete Anchor Points, but my iPad Mini 4 definitely shows Delete Nodes. Not sure if that’s a minification thing for the small screen, or the function has been renamed at some point. 
Official documentation: The Inspector | Vectornator Learn
Away from my Mac Mini at the moment. By the look of the manual, it’s in the Path sub-section of the Inspector, and in the manual it is labeled Delete Anchor Points. See the official documentation: Mac Style Inspector | Vectornator Learn