Thanks Phil,
use case is related to an external system which can be queried to retrieve new plants to be inspected. For each new plant there are many infos that shall be added in the inspection forms such as plant code, description, suppliers, ecc.
Thhat means that are at least necessary cascading selects with dynamic lists and perhaps other constrains (to be verified).
Currently the survey owner manually insert all these data and publish updated form, but in the future they want that a server process query the external system and perform all the job.
I don't know if I can use select_x_from_file for upgrading lists that are used in cascading selects (I tried but it don't work and probably i'm doing something wrong), which should solve 90% of the scope. If it is not possible I guess that I have to wait until the dynamic lists via feature service enhancement.