It’s possible that I misunderstood you before. If default skeletal mesh is ok and your mesh scale looks wrong, it could be a bug. Can you make a screenshot or - it always helps - send me the mesh itself (ykasczc@gmail.com)?
There is another problem. Pelvis is a parent bone for both spine and legs. When you apply legs animation by ‘Layered blend per bone’ to pelvis, it overrides pelvis position generated by plugin.
In my demo project I apply strafe animation only to thigh bones. See ABP_VRIKAvatar’s anim graph. This approach has a problem too: as legs animation rely on pelvis, pelvis bone removed from the animation partially breaks it.
Another approach is to apply strafe animaiton to pelvis and legs and use PoseSnapshot since first spine bone after pelvis. It gives another problem: as strafe animation change both rotation and location of pelvis bone, it affects whole torso position and adds some error to head and hands locations (although you can fix hands with TwoBoneIK node). Note that if you use strafe animation as a base and add PoseSnapshot above, your strafe animation overrides root bone position. And if you use a mesh without separate root bone before pelvis (like Mixamo), it could give more errors I never faced.
I suggest to use the first approach. If you have an idea how to improve it and get clear blending, please let me know. I’ll try to implement it in the plugin.
What flags would you want?