Solutions!

A user in our Discord found a solution to the rigging problem. Cinema 4D has some rigging tool that allows you to replace the Skeleton with the UE5 one. Many programs can do this but Cinema 4D does something special that makes it work... It some how, through black magic, stores the morph data.
There are still some kinks to be ironed out, but we're 90% closer to a working resolution.