"Commercial aerobatic operations in an aeroplane built in 1939?"
Very relevant observation. Tiger Moth adventure flights seem to have been involved in a disproportionate number of fatal accidents in recent years.
As was mentioned above, it is unlikely they were designed to be used for commercial aerobatic operations some 75 years later.
Maybe it's time to stop using the "Limited" category as a loop hole for these types of operations and retire Tiger Moths to Private use only.