I have found the data client is better at parsing the data from the client side container and building this in the event-data model. When we use the data client we receive the items object from the datalayer for purchases which we do not with the GA4 client. So I am thinking about just using the data client for everything instead. The problem is that when using the data client to trigger the GA4 tag . the data is not sent to the correct GA region.
I would not recommend using Data tag - Data Client to send data to GA4 or any Google platforms (Floodlight / Google ADS etc).
Google tag automatically collects some events and generates quite a lot of automatic data that is needed for correct operation of GA4 / Google ADS etc. So it is unlikely that you will be able to replicate this completely and the quality of your tracking will suffer a lot.
Data tag - Data Client is a great source of data for any non-Google tags (Meta, TikTok, Klaviyo, etc.).
As per your questions - GA4 itself determines which endpoint to send data to, you can’t influence this and Stape can’t influence this either.
the main reason for using the data client/tag was that we have some events with parameters as arrays which the GA4 tag/client does not seem to recognise whereas the stape one does.