Sure but one will have to purchase the Decimator plug-in.
Typical use is to first export the LOD 0 model, any model, and import into UE4.
You would then apply Decimator and dial in the level of detail you want for LOD1 and export. In UE4 you would import the LOD into the base form and set the screen distance. Repeat for additional LOD’s and the expoter will maintain the skin weights and morph targets.
P.S. The only real difference as to use between G2 and G3 is the G3 supports cluster shapes where the G2 does not but only matters if you wish to use cluster shaping or data driven facial animations.