Speed-dating layout — each cluster is its own table of two facing rows: ■ Stays keeps its chair; ▸ Slides shifts one seat right each rotation, so everyone meets a new person. Rename a table by typing in its title, drop a seat with × remove, add one with + seat, or add a whole new table at the bottom. The blocks up top recalculate as you go.
Optional second round — one long pair of rows across the two sides. ■ Tech stays; ▸ Commercial slides one seat right each rotation. Each column is a starting pair: Tech on top, their Commercial partner below. Rotations are capped (see blocks) — meeting all of the other side would run too long, so people meet several, not everyone. Scroll sideways for all pairs.
Keep this on the room screen. Names & timings save on this device; the screen stays awake while the timer runs.