Posting in this thread as it's the oldest.
I made a first release of my tool:
https://github.com/quietvoid/dovi_to.../tag/0.1.0-fix
It can be used to create an RPU file from a profile 5, 7 or 8 HEVC encoded file.
Commands:
demux: Demuxes single track dual layer Dolby Vision into Base layer and Enhancement layer files.
extract-rpu: Extracts Dolby Vision RPU from an HEVC encoded file.
More info in the README.
Enjoy.