What you'll get will depend on how you try to access the data. That experimental feature has a side effect of determining the buffer size that will be used when you try to load data into a local collection, which is probably what you are seeing.
For example, let's say you set the data row limit to 5, and add a data source to a SQL table (Products) that has 1000 items. If you have this expression:
Collect(collection1, '[dbo].[Products]')
Then you'll only get 5 items in the local collection - that's also controlled by that setting.
Even if you use some filter expression, you'll only get 5 items:
Collect(collection2, Filter('[dbo].[Products], ItemsInStock > 10))Now if you insert a gallery (which is a control that knows how to deal with delegatable data sources, essentially requesting "new pages" when the user gets to the end of it), and set its Items property to the data source, then you'll be able to see the entire table (or filtered table, if you used a filter expression).