Assumption is that you install package(s) form the trusted source publisher (in IPS terminology 'repository' is called a publisher). Do not install packages form untrusted source or from third parties unless you accept the risks of installing third-party binary packages.
We are going to do do update testing, so and we do not need any additional infrastructure at the moment. We will reuse currently unchanged /hipster-2015 repository (at pkg.openindiana.org/hipster-2015) as the nearest to the latest positive update reports from /dev.
There is one more update target, that is OI hipster 20160421 snapshot, but there is at the moment no separate publisher infrastructure for it.
It is more important to confirm at least one positive working update target to test updating in detail, therefore even just testing update to hipster-2015 can be enough
The point of testing is not that you end up with running Hipster in production right now, but, but to go toward updating renewing /dev update , thank you for your testing reports!