Install unsupported latest versions

[#1]

Can I use ambari to install the very latest and for hdp still unsupported versions e.g. Of spark or accumulo?

I don't mean the technical previews here but rather the current version of these services.

[#2]

@George Vetticaden

you can install in backend. But this is not recommended.

[#3]

@Ashnee Sharma

is there any documentation how to perform this task?