I've bought the Sosumi and the Obsidian (I'd have bought the Opal, but I don't have anymore space). Anyhow, most of what you show and explain, in the video and manual, is clear. However, maybe you can explain the attunverters a bit more clearly? In the video (@0.56) you say the attenuverters and cross modualtion change amount and direction. So, in the video, when you turn the green's control towards minus what is happening? We see both waves changing, but how is each LFO being influenced? In the YT example, when the attenuverter is turned to minus, is it 'less influenced' by LFO 2, or is it 'influencing less' LFO 2? Or, maybe something else?
Secondly, you say that whilst nothing is plugged into the CV control, the LFOs cross modulate. I seem to remember in the manual you say if you wish to stop the cross modulation you plug a dummy cable into the CV (or another LFO/VCO). What happens if you plug something into just one of the CV controls, does the unplugged LFO still cross modulate - with the one that is being CV controlled?
Lastly, a little design suggestion - if you update - please make the rack holes oblong (not round) so they fit more easily in a rack. The spacing horizontally is a little tight for some patch cables. Maybe have your jack inputs slightly offset per row - not unlike a saw wave! Example (top row): sym OK, CV1 up slightly, CV2 ok, sym up slightly. The spacing vertically is perfect.
I hope all that makes sense?
Anyhow, the Obsidian is really interesting to use, fantastic work. You could say it's 8 complex LFOs running at two speeds, which is amzing in such a small module. The Sosumi is excellent too, but there's less to understand on that module (it just sounds). Great work, bravo.