Purpose of Module def & new doctype in production mode

It is possible to add new module def and doctype from the site itself.
Curious to know if it can be used to make new module/doctypes directly from here while in production mode (not changing to developer mode)

Use case - Could be very handy for making simple Reports/checklists for anything from quality to 5S & housekeeping.

In production mode you can create custom doctypes. Module def is not possible.

Where’s the location of custom docType in production mode?
I’ve created a new docType in the production mode but doesn’t appear in the module app folder

It will be directly loaded in the database.