Regarding Mac and Linux availability - the builds for these are present, but we will need 3.08 RC1 to be made available for said platforms first. From the development lead regarding 3.08:
First of all, apologies for the delayed release and for the lack of communication on the forums. It wasn't planned, but we had to sort out various important problems in Octane and its ecosystem (still not finished for OSX and Linux yet) and this took a lot longer than we hoped for
With this release we should be back to the normal release schedule. We are trying to wrap up this development cycle as quickly as possible. In parallel we also have been working on (hopefully) exciting new features. More about these soon.
You will find more information here: https://render.otoy.com/forum/viewtopic.php?f=33&t=65686
The builds are ready to go for all platforms once this has been resolved by the Core Team. Apologies for the delays still affecting our non-Windows users.