I took a quick look at that some time ago, but it wasn't that trivial for me at least unless I would rewrite parts of the element table management around sorting. Happy to accept any patches there of course.
@masonbee The memory limit setting is the "maximum memory" before which the app is killed for over use. It is not "reserved memory" i.e it's not pre-allocated to the app and thus cannot be used by any other app. The "maximum memory" simply ensures that a single web app cannot bring down the whole system.