As far as I understand, HW no longer supports Poser versions older than 11, and neither does Renderosity, or even SMS before them. Somewhere between 11..0.6 and 11.1, Poser has become incompatible with older versions, and I am not sure if that has happened by accident. And even before that, Poser 9 and 10 already had critical bugs on the content creation tools that made them unusable to me. Some were fixed in Poser 11.0.4, but older versions (9 and 10) will never be patched, and are no longer supported by anyone. I have tried to make my products compatible with them, but backwards compatibility has become pretty much broken and unreliable. I would think some things *should* work, but they don't, and they will never be fixed.
In addition, P9 doesn't understand unimesh skinning and subdivision, while P10 doesn't support PBR materials. I am pretty sure the new Dawn materials are using PBR shaders, and that alone will not work in older versions. With my body type series, even morph injections wouldn't work in Poser 10 because of incompatibilities with the new animatable origins in Poser 11. I had to hack the files to make them work, but I don't do that anymore. Having that said, I wouldn't count on Dawn 2 working in Poser 10.