If this only for yourself & any future exports of characters are to Blender, then creating a pose library in the source .blend might be an option. You could then append the pose library to a different .blend & assign it to another skeleton.
It is a little tricky using Append with pose libraries. Pose libraries are just a specific kind of Action, so the pose library will be listed in the Action "Folder".
That said, it might not give the exact same result, especially with face bones. While the all the same bones are in all exports of the same skeleton, they are custom positioned for each human. I am not sure if the .bvh route avoids this either.
One area I use this is for finger poses. I have a
.blend, with the default skeleton & finger IK bones added from the
community plug-in. I never modify ANYTHING having to do with fingers in MH. If I also add finger IK bones to another skeleton, all the poses work. Even in toddlers (source is adult).
FYI, I further convert the poses to shapekeys later, so can be exported to a skeleton poor environment, WebGL. They work well as long you do not slow things down too much,
see.