I'm a DJ/TUI nerd and as much as I want to like this, I don't think the keyboard will ever be the right input or mode for DJing. Maybe my mental model is an outlier, but multi-point physical controls are critical for so much of what's happening while DJing — the master level controls, effects, cueing, individual track controls, and even just being able to physically manipulate playing tracks. It just doesn't map to a TUI, or perhaps more importantly, it just doesn't seem fun. How does the TUI transition this? What makes a TUI the right interface?
I think for algorave stuff it's great because I'm already at the keyboard, but I totally agree with you otherwise. I was thinking (way too complex at this point) of adding control macros to be able to "turn" 2 knobs at once, because that's something real hands and knobs can do, but not this TUI atm.
I mean, you theoretically still could have that, USB decks send MIDI signals (even though I found it a bit obtuse trying to get my FLX4 to control anything except VirtualDJ - I was trying to map it to grandMA lighting controls). The TUI here could be primarily a presentation layer. I think the main benefits would be a) more hackable than VirtualDJ and b) it looks cool.