In the last 3 days we went through 2 test builds of the core SDK, one test build was due to fixes we require for SU to enable material, object, target, etc picking in the Octane viewport. The second test build was to fix a bug in the core scene export. Both of these were essential.
The 3.06.1 SDK stable release has now been made and we are working at full speed for integrating it, and getting it tested internally. Since this is a major upgrade (not only to SU plugin but also Octane itself), we will be releasing it as a TEST version not suitable for production work, until we have ironed out any other issues that come up.