XRef Materials might do what you need. I don't have any experience with them, though.
Another option is to convert all of your materials in one file to Corona materials (sounds like you've done this already). Then, save those out to a new material library. In Slate Material Editor, look under the Material/Map Browser, choose New Material Library..., then select your materials, right click on your new material library name and choose Get Selected Materials/Maps. Right click the library name again, go down to the material library file name and choose Save. Now open a scene that you want to update the materials to Corona materials. Your material library should still be in Slate Material Editor. Right click the material library name and choose Update Scene Materials from Library. That will update the scene's materials with ones from your library that have the same name.
I do this all the time with Civil View vehicles.

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Max 2025, Corona 12