Are all the endpoints listed in https://docs.aveva.com/bundle/insight/page/522189.html really necessary if the customer just wants to publish data to Insight? His it-department are very reluctant to do so!

The list from the documentation is more comprehensive than simply publishing data. However, more of that list is required to support the initial login/registration. After the data source is registered, only the single "nch" endpoint is needed. The exact endpoint varies by region, but for North America it is: nch.online.wonderware.com

The current "allow list" is always maintained at: insight.connect.aveva.com/.../OnlineConfigPush

There is a PowerShell script to format the list nicely for easier reference. It includes some high-level functional grouping that indicates which features require the associated endpoints. 

The list from the documentation is more comprehensive than simply publishing data. However, more of that list is required to support the initial login/registration. After the data source is registered, only the single "nch" endpoint is needed. The exact endpoint varies by region, but for North America it is: nch.online.wonderware.com

The current "allow list" is always maintained at: insight.connect.aveva.com/.../OnlineConfigPush

There is a PowerShell script to format the list nicely for easier reference. It includes some high-level functional grouping that indicates which features require the associated endpoints.