Hi Dave - Thanks for your feedback. We usually recommend other 3rd party modules that have better export / search/ sort routines such as OWS or our Dynamic Views module. Dynamic Views has a built in interface with Dynamic Forms and other powerful features such as unlimited search fields, exporting to excel, etc... This might be one option they want to consider.
Another option is to review demo 14 and demo 21 at
http://www.datasprings.com/formdemos. These highlight storing the data into a flat table which is much faster to retrieve the data from instead of the relational database tables.
Thanks!
-Chad