How can I send my Sphere tracks to other people for mixing?

There are two main options. One is that you can "freeze" the tracks so the processed audio is saved to disk so then you don't need the plug-in. Many DAWs, such as Pro Tools, have a freeze function to do this automatically, or you could bus the output of Sphere to another track and record it. If you are using a Universal Audio Apollo you can also commit the output of Sphere by using "UAD REC" mode.
The other option is to ask the mixing engineer to install the Sphere plug-in. Anyone who registers on our website can download the native/HDX Sphere plug-in. This option allows the mixing engineer to choose mic types and other Sphere settings.