v4 - when downloading results, legacy jobs get redundant naming (cryosparc_PX_cryosparc_PX_JXXXX.mrc) but v4 jobs do not. is this intentional?
It is intentional: file name conventions have changed with the transition between CryoSPARC versions 3 and 4.
For older files whose download names contain two project identifiers, the first project identifier is the important one.