Hey there!
Arigify is an add-on i made, that is aimed at making character animation workflows for 3D engines with Blender/Rigify easier, by removing unnecessary clutter. It supports arbitrary character topologies. It was tested with Blender 2.82, and the most recent versions of Unity and Unreal Engine 4. Check out the teaser video and the product description on Gumroad for more info. Feel free to ask anything.
Teaser video:
https://youtu.be/5AksScAexQQ
It is available on Gumroad:
https://gumroad.com/l/arigify
edit: added new teaser video to reflect up-to-date processes