It's hard to write such a thread since xen support is obviously removed. But there's a dilemma that Mikrotik has to face with. Since version 3.22, Mikrotik has no decent version to support xen vm's. No installation what so ever support memory configuration global settings parameter after 3.22.
When we ask about it on the forum, they're easily advising us to move KVM versions. We would like to do so but we have decent piece of hardware's running RouterOS with Xen and they don't have support for VT enabled cpu's.
Mikrotik has to release a patch version like 3.31 or a descent xen package for 3.30 at least to support the customers using Xen. We're very satisfied with the Major 3 version of Mikrotik. I think, we all deserve such action as paying customers.
Regards