Thank you for the detailed response and materials.
If you don’t mind, more remaining thing to clarify..so does this mean that the only provided bval (fileprefix.dwi.bval) and bvec (fileprefix.dwi.RAS.bvec) files in the regular output are technically incorrect for the distortion corrected diffusion data (fileprefix.dwi.RAS.correct.nii.gz) in native diffusion space? (not T1 space). Or are they correct, and they would only be incorrect if tried to apply to diffusion data in T1 space?