Hope to start testing Slate Desktop on Mac soon.
Yesterday I received this information from Tom:
In a couple of months, I'll be rolling out some new read-made engines for some language pairs where public training corpora are available. Then, translators without TMs can use Slate Connect ($49) with the ready-made engines for less than $30 each engine. This configuration also makes it easier to support a native MacOS Slate Connect running on MacOS, but building engines will still be a Linux or Windows task with Slate Desktop or Pro.