Dear All,
Hi there, Mark Coniglio creator of the video software Isadora here.
For all of you that want Syphon into Zoom, I created a free tool for macOS called Syphon Virtual Webcam. Details, download instructions and short tutorial can be found on the TroikaTronix forum.
Note that some users had a bit of trouble with Zoom. If you have difficulties, follow the procedure in the READ ME included in the disk image to reinstall Zoom 5.1.2 client and Syphon Virtual webcam. That seemed to solve any issues people were having.
Best Wishes,
Mark