Hello and Welcome Zak.
Unfortunately I am not familiar with C4D and AE neither so i cannot really help you on these points.
Overall it looks like you output a result that is excepted so it should work.I didn’t know the trick sRGB to Linearized sRGB so After can still apply the transfer function himself and be happy.
Some notes:
OCIO Raw to ACEScg
This is equivalent to a “no-operation” so you can remove it.
I uncheck the “Enabled” check box under Color Management in the Redshift Post-Effects
Not sure it is needed. I think in the Redshift Render settings you can just tell him to not apply any post effect on exported files, unless it works differently in C4D
I’ve pre-converted to ACEScg (Utility sRGB Texture ->ACEScg)
Maybe you just didn’t precise it but there is not only HDRIs that need to use Utility-Linear-sRGB, if your source has a linear-transfer function it should be treated as such. So for any EXR, if no colorspace is specified, you can assume it’s sRGB and probably wrote using a linear transfer function so you will need to use Utility-Linear-sRGB.
Hope you will find someone that knows how C4D colormanagement work to confirm your workflow.
Cheers.
Liam.