I just installed a new valley pan on my 6.9 with HyperMax turbo setup and examined the drain/ baffle config to assess need to add more drain holes below the turbo oil drain- I realize not CDR but reuses same hole in valley pan. Confirm there are 2 layers but the lower layer has an open aft edge so it should drain unrestricted; the upper layer had several- 4 if I remember correctly- maybe 1/4” drain holes which seemed quite possible to partially get obstructed by “carbon” over time so did add more punches drain holes thru top/ 1st layer.
But, and this may not apply to your CDR drain issue, I discovered when I installed the HyperMax turbo oil drain that the flat end of the drain hard tube, which slides down into tho original CDR hole in valley pan- was sitting flat and hard onto the surface of the upper valley pan layer. So I ended up punching the holes thru the top layer immediately below the grommet anyway to ensure drain down of oil flow. Maybe or maybe not your situation but just pointing out a possible aspect to consider.