Hi markelliot2002,
There were no images/textures in your file. However, I recreated all (of course not knowing the color information nor the resolution, etc.). But several channels are not supported via MTL import nor export.
Screenshot
https://www.amazon.com/clouddrive/share/SrJW8yTZva2IZPb660eyYz4fQnV6yhuR3Wdg1G1q3Y6
I checked the MTL that you had and placed the materials where I believed they should be. Then exported this to see how the MTL would be written.
The manual of Dimensions (I have to admit, I haven’t used it in over two decades):
https://helpx.adobe.com/dimension/using/supported-file-types.html
Here it states clearly the vast limitations of this. 2K textures max, which might be small if not tiled.
The manual doesn’t tell any specifics of their MTL use, so I searched for the white paper of MTL, the best I found is here:
http://paulbourke.net/dataformats/mtl/
The logical path would be that Photoshop can open the results of Dn.
The idea was to use a native Adobe product to get the dae format.
Not a result as expected.
I tried to write out the OBJ/MTL from Ps. Only two textures were saved in color and opacity.
Only two textures are seen. The same that arrive at Cinema 4D.
You might check with the support on that:
https://www.maxon.net/en/support-center
However, I’m pretty confident that there is no current option to get more than the two channels.
My suggestion is to open the MTL file in a text-app and read what goes where. Whereby alternatives are possible. (Suggestions)
map_Pm x0/Plastic with Lattice Pattern_metallic.jpg (Reflectance channel)
map_Pr x0/Plastic with Lattice Pattern_roughness.jpg (Diffuse or Bump channel)
map_Kd x0/Plastic with Lattice Pattern_baseColor.jpg (Color channel)
disp x0/Plastic with Lattice Pattern_height.jpg (Displacement channel)
map_d x0/Plastic with Lattice Pattern_opacity.jpg (Transparency or Alpha channel)
norm x0/Gelatin 3_normal.jpg (Normal channel)
My suggestion, model in Dn if that feels more comfortable, but surface and light in Cinema 4D. As I typically say, wearing my Mentor hat for a moment, get out of your comfort zone and dive into Cinema 4D completely. The options and workflows are undoubtedly different, but you might see very quickly how much more is possible.
All the best, satay safe, stay healthy.