Cesium-Native Functions

I recently stumbled on the “cesium-native” project. We have applications that use CesiumJS and fly live/historic flight data. Our flight data has elevations in MSL, so we currently use “EarthGravityModel1996.js” and the “WW15MGH.DAC” file to convert the altitude of every track point to a WGS84 height.

I’m wondering if there are methods in “cesium-native” that would allow us to convert MSL to WGS84 in a more efficient manner?