I contacted Alexei through his instagram and he responded ! I was curious how much music was written for the series he said he composed around 20 to 25 mins of music for each episode. Sometimes the themes were the same, but some music was not used as well. Roughly around 60min of original music which would be a good CD release.
He said he's also inquired with Lakeshore Records as they did a digital release of I am Not Your Negro - but he hasn't heard anything back from them yet.