Basic zoom doesn’t use stream keys in that way. You may not need OBS at all, have a look for a bit of software called “camtwist”. This allows you to pick a syphon source (Resolume!) and then presents itself to the system like a webcam. Zoom can “see” camtwist” as a usable source. I hosted a family q...
I’m guessing Arvol will say Touch Designer? I’ve started using a combination of that and Companion. Companion being the initial trigger (simple messages). Touch designer listening to companion and then sending multiple messages as needed.
I use WYSIWYG. From Cast. You can create surfaces and add NDI sources to them. Look at you with that "Baller" Money $$$$$ ;) Luckily I use it for my normal work! Luckier still I don’t pay for it myself! For static renders I prefer to use SketchUp. Just export a png from Resolume to attach...