This is the bit i need help with..... "Anyway, assigning this profile in an action, which you then run as a batch, is straightforward."
I can assign a profile to one pic at a time, but how to you do a batch? I'm not finding it straightforward lol
Have the first file open.
Open the Actions panel, and create a new action. Name it. Start recording, there's a button at the bottom of the panel, which lights up red.
Do whatever you need to do. In this case it's mainly Edit > Assign Profile. I'd still recommend you save the result out as a copy to a specified folder, which you can do here as the next step (there are other ways to handle this, but that's a different subject better suited for the Photoshop forum).
Close the original without saving. You don't want to overwrite your originals.
Stop recording.
Open Bridge, select the files you want. Tools > Photoshop > Batch. Pick your action and go.
Now, I don't want to have an opinion on the procedure itself, except to note that the raw file must at some point be rendered into an RGB file before the icc profile can be generated. I'm not sold on the accuracy of this, but be that as it may. I would still recommend that you keep your files in a standard color space.