Looking at the KB article again it does seem as though there is another thing to try, which is to remove the CR runtimes installed with SFA (by renaming a folder?!?), remove the SFA config files, and re-run Sage 100 workstation. Then (presumably) the new SFA would run using the old runtimes.
I wonder if this would work for a test Sage 100 v2018 workstation install. Hmm...