I've tried a colour effect (Mood Blobs, I think) but that didn't produce any output, though I could see the single mapped LED in the web interface pulsating red.
Here's the log: https://pastebin.com/3vwrtx6A (might be obvious I don't really understand the effects controls very well)
I was in the remote control page and I see a purple colour set via the web configuration has a higher priority than my source and is selected. No visible output from the light at any point still, even if I swap between the sources - still relatively unclear as to what DMX channels are being controlled here (though I'm aware this takes time).