You may have noticed that currently PM will not allow you hide/remove the remove the X-AspNetMvc-Version HTTP header from its sites.
This is by design, currently the X-AspNetMvc-Version HTTP header is hardcoded in to the sites. An enhancement request (84672) has been created detailing the feature above.
The product team will evaluate the request and this feature may become available on a future release of the product.
Please refer to this article for updates or contact support referencing the Enhancement Request ID: 84672.