It appears that SlamData have removed the direct download link to the installer that I had previously arranged with them. Additionally, while the SlamData 2_5_6 version will install, it no longer appears to run due to some obscure error. And new versions cannot be directly downloaded as they apparently now require a subscription - even for the Community Edition.
So the TL;DR is that SlamData is not working for any prototype VM provisioned within the last couple weeks. I am reaching out to SlamData to try to get this resolved. It may also be possible to build it from the source, which I will investigate as time permits.
In the mean time, I’m going to shift focus to ElasticSearch / Kibana. It is far more accessible and seems to be the ubiquitous choice for analytics visualization.