It would be useful to support materials that use the Diffuse BSDF shader, which is simpler than Principled BSDF, and should certainly be supported for non-PBR workflows.
This may require either a workaround in blend2bam or an upstream feature request/PR to the glTF exporter.
If we decide against this, then there needs to be a note in the manual saying that only Principled BSDF is supported.
It would be useful to support materials that use the Diffuse BSDF shader, which is simpler than Principled BSDF, and should certainly be supported for non-PBR workflows.
This may require either a workaround in blend2bam or an upstream feature request/PR to the glTF exporter.
If we decide against this, then there needs to be a note in the manual saying that only Principled BSDF is supported.