The previous version I wrote used object_types and attributes to build the metadata model first. At some point you could then generate the database code and run it. You could also modify the metadata later and generate the alter table statements. It seems like the CR and object_types should work the same way. I just started using the CR so I'm not all that familiar with it.
The previous version I wrote supported objects in objects to any depth although more than 4 is not really that practical. It also supported 1 or more via max_n_values. I did not use the templating system because it was too slow (we had hundreds of objects per form). I think ad_form will work fine for any reasonable form. There needs to be an storage mechanism similar to generic but supporting multiple values per object. I also implemented a not so generic storage that could store datatypes like numbers and dates in something other than a varchar(4000).
