The exact sequence to run at the Germany expo. For each scene: what shows on the screen, the line to say, and the fallback if it wobbles. Rehearse straight from this.
"This is a working demo of real, buyable hardware, not a finished product. The measurement is a rough size, plus or minus one to two centimetres, not a hologram. The translation has a short delay. One light glass plus one phone do the three jobs together." Saying this up front turns every limit into an expectation you set, not a surprise.