6 and 8 is a significant difference on this “platform in a platform” solution we have with AppSupport. Phone continously running out of memory on X10II with its 4GB is a huge headache, and people are reporting better but nowhere near ideal outcomes on X10III.
I tested all available hacks on X10II: tuning OOM killer, increasing zram, expanding swap on internal memory, but it all fails miserably one way or another. More more more physical RAM is the only solution, and 8GB is probably the real minimum, but compatible device availability is what it is (or isn’t what it isn’t?), and Jolla’s administration troubles have delayed progress in getting to better devices by at least 1 year I’m sure… Thoughts and prayers from here on out though 
!