This feature is something we would really like to see in Testrail. I am a fairly new user to Testrail and have been happy with most aspects of the software. That being said, it is a big enough issue in our workflow that if we find a comparable software that will already allow this we would switch. I would prefer to see it added to Testrail as we are already self hosting and familiar with it.
At this point with the type of replies that are being sent it seems like they are trying to use the lack of functionality on this to drive the upgrade of licenses. I would warn that in general lack of functionality is a bad marketing strategy.