I think we should only do "old_ref=S285", because we cannot confirm that it's X622.

The secondary road (X622 you mentioned) should be the old S285.

The new S285 (the primary road) is newly built, but is not fully completed on the map yet.

Several online map in China tag both of them as S285.

Once we finish the primary road I believe that we can remove the ref tag from the secondary road.