Heh, I wonder if the Syphon update I was reading meant macOS 14 (or I just messed up), but yeah, things have changed for newer macOS versions. Both the information you shared and the information I shared will be useful to anyone using macOS, use whichever one fits your situation. I'm on 15.1.1 and Syphon absolutely no longer works, but the built-in "macOS Screen Capture" does.