Hello !

I am glad you are enjoying the extension!

I have been thinking of that feature for a while now, this is something I have wanted to explore.
I think the best way to do this would be to implement a plugin that would allow inclusion of content (any content) after a certain number of news items (like after every 4 articles).
It has to be done so that it does not 'break' the flow of the items.

This is something that I will definitely work on, but not for a while since I am trying to prepare for Joomla 4 right now. Any new feature pushes back Joomla 4 releases, so I need to keep focus on that. 

In the meantime, to 'fake' that functionality, you could just duplicate the module. The first module, set count to '5', start at '1'. The second one set 'count ' to nothing and start at '6' (just a suggestion).

It will add a bit of extra code to your page but this will allow you to add ad content between the 2 instances.