Regard to the material convertion,
In 3dsmax there are two type of image both work with opaque channel mapping
1, an image in png type with a transparent background, which will be correctly translated into alpha image, the convertion will be correct.
2,3dsmax allow black-white jpeg as the opaque mapping, but this type of image is considered as greyscale image instead of alpha image in octane,
after translation, though the jpeg file name is the correct, octane will not find them (there is no jpg type selection for alpha image) and the opaque mapping will be actually lost. so there is always materials mistakenly converted when opaque channel is using a black background jpg,
Manually we can fix it, but unfortunatly we users may not realize which material is correctly converted which is not.
All versions have this issue.
Jim