DLP supports Haansoft Hangul for file type identification. Both HWP and HWPX file types are part of Haansoft Hangul.
HWPX file type is currently unsupported in DLP.
DLP currently only supports the HWP file type and not HWPX. Feature request (ISFR-2628) exists to add support for HWPX file type in a future release of DLP.