I'm currently working on implementing the WebSDK for Adobe Analytics and I'm wondering about advantages of using a schema with a custom field group over the out of the box Adobe Analytics schema.
A custom schema may help if you want to use it as the structure of the event-driven data layer on the front end which can provide a clear semantic meaning of each attribute. However, you will need to map those custom attributes to the corresponding attributes in the OOTB schema when setting up the datastream, so those information can go into the correct evar/prop/event.
If you use your own custom schema yet you want data to appear in Analytics' props/eVars/events/etc, then you will need to setup your own Processing Rules in the Analytics report suite to map the context variables (that are derived from the Web SDK hits) to your Analytics variables.
A custom schema may help if you want to use it as the structure of the event-driven data layer on the front end which can provide a clear semantic meaning of each attribute. However, you will need to map those custom attributes to the corresponding attributes in the OOTB schema when setting up the datastream, so those information can go into the correct evar/prop/event.
