It's not easy to replicate. Contrary to common belief these issues do _not_ happen for everyone. I don't get any of them, for example. My memory build up was solved with 10.0 and the microstutters I once had were fixed in 9.0. Issues we experience ourselves we address as quickly as we can. The survey we lately did also showed that while a notable amount of players undoubtedly get such issues, the vast majority noted explicitly that they do not have any.
The only way we can identify these issues without getting them ourselves is what I mentioned in my comment above. We need players actually experiencing them to use a development build and provide investigation data to us. That is a complex task to do, but there is no alternative to it. So every player willing to get their hands onto that is extremely appreciated and likely allows to address another performance issue for multiple people. It's just important to see under which circumstances and which server environments issues happen exactly, what player-related factors apply and getting the technical data while an issue is happening. We unfortunately aren't magicians and can't fix issues without having any data about them, as much as we'd like to be able to.
So, please, anyone that feels they have a bit of time and will to provide us that data - you'd be heroes. It's extremely hard to find players that don't only complain about issues, but are also willing to help us out getting the data we need. And I fully understand that many just don't want to go out of their way to help, they're customers after all and can expect something else. That is absolutely valid. But we have no other working methods to get what we need to fix the issues currently.