I have done something similar in another platform. Basically you are just creating another meta-data layer to control field labels and which fields to display for each form. I would suggest you do this at the form level, rather than the entity level, as then you can have several forms for the same entity with different attributes displayed, all controlled by data. It's still going to be difficult to have a good looking UI form unless you have a really simple layout.
As Sander indicates, this is possible, but you need to step up a level of abstraction, and forms need to be generic, so i think it has in general limited usefulness. The domain model then would look like the one provided by the model reflection module. You need to have something like:
EntityType (name : String) AttributeDefinition (name: String, type: String, owner: EntityType) Instance (entityType : EntityType) Attribute(instance : Instance, attributeType : AttributeDefinition, value : String)
Associations can be modeled in a similar fashion.
Off course, this approach would be many times harder to maintain then 'going back' to the modeler. Using this approach means: No Meta model validations, no keeping data on migration, no designing forms etc. It can be done, but i would advice very strong against it, unless you have a really specific purpose and limited functionality with such a model, and no requirements concerning usability/ the GUI. Sooner or later your client will ask to be able to click through on an attribute to open a form and you are hacking for hours for something which could done in 2 clicks in the modeler. No more agility. I think it is interesting to find out why the client is asking for such functionality?
Off course, if he would like to edit any data in a generic way, and modify any entity/ attribute definition, you could deliver the appropiate database client, for example PgAdmin ;)
Good advice. I am leaning toward just making this work in the modeler. I have only 93 different tables and I am not willing to create dozens of microflows and make all sorts of complexity. I will take the advice very seriously, thanks.