If you can pull it off, it would be worth being there to see what's going on in person.
I dunno what the dyno plan is, but you can maximize the time and effort just by being there and learning what they are doing. Depending on the situation, you might be able to get more out of the session.
Some people are just doing it to break in the engine and seat the rings. Others to get tuning info (look at fuel consumption vs the 'afr' vs power. etc