I don't quite know how to answer you without sounding like a fanboy, but have you tried using ReLive to stream instead of a third party program like OBS with a beta version plugin?
If the stream quality is at least half of the recording quality I've got with it, then it should be still extraordinary and I have no idea why you have issues with it.
Could you perhaps show us your ReLive settings, OBS settings, and a sample of "bad" streaming quality you have got while using these?
If developers says that are errors in x264 encode so they are to in ReLive . RX 480 from hardware not support B-frames(think that is esential thing) so how magicaly will be support and working in ReLive ? MikhailAMD made internal tickets to fix errors , so when there are errors so how will be no errors in ReLive when third party software and ReLive base on this same SDK and drivers? Developer says:
Xaymar"... In the OBS plugin I have had the RateControlPreAnalysis option for a while, except I used it as a boolean. It did some wonders for the output quality there, so is 17.1.1 missing the necessary VCE firmware update for AMF 1.4?"
rigaya" I also cannot find speed impact when I switch on pre-analysis at my environment, it's almost the same speed whether the options is on or off."
So something its not working like its should do work.