In my experience, the memory management in QV 12.10 SR3 is pretty much the same as in 11.20 SR16. If a user creates an object which necessitates a large amount of memory to perform the calculations or creates a bad expression resulting in a Cartesian product, etc., Windows may, at its discretion, switch over to paging. This isn't itself a QlikView issue, per se.
See the Release Notes for 12.10 IR (https://da3hntz84uekx.cloudfront.net/qlikview/12.10/12100/QlikView%2012%2010%20Release%20Notes.pdf), section on "What's New in QlikView 12.10." There isn't any mention of new mode of memory management.
Hope this helps