Good luck, and please do share any success stories.
Heeding my own request, I am hapy to report that while the mid-April release of the Radeon Pro software resulted in instability and much flickering on my Kubuntu 18.04 official release installation, the May 3 release (definitively after the April 26 official Ubuntu 18.04 and flavours release date) - installed flawlessly and I have only noticed one glitch, that have not since been able to reproduce - a slowing to a crawl of darktable (but no other running applications).
So, I am happy to recommend downloading and installing from here the amdgpu-pro-18.20-579836 version.
I’m running AMD A12-9800 (APU with Radeon R7 Graphics - 8 graphics cores). Your mileage may vary.