Defining default text for a default field in a Dex product

I cloned the Event Dexterity CT to create a new Event type identical to the existing Event (I need different CT to manage my content rules more effectively)
Since the two new Events, will have standard text (e.g. title, location, e.g.) unique to each CT, I wanted to add default text. This is easy for fields I add; however, I can't see how to do it for the default (greyed-out fields)
I tried the "Edit XML Field Model" where I thought I could add text. However, only the fields I add are defined there. the others are somehow controlled by the namespaces or whatever.

so, is there a way to create default text for these "default" fields that included as part of the CT definition in Plone?


The other fields are managed by behaviours, this does make it trickier. I'm sure there is a way but not sure how straight forward it is. That's an interesting problem and we should really try to figure out how to make it easier.

Here's a way but unfortunately it isn't a TTW approach, which means creating a custom add-on, which certainly defeats the convenience of what you're trying to achieve see:


You could do something more "hacky" by defining fields yourself and disabling the default behaviour, at least it would still be through the web.