I totally agree - ZRAM isn’t magic and of course it will fall flat on its face for loads of encrypted, compressed or pure random data. In my limited day to day usage I just never hit that situation, so far.
Again, I fully agree, I wouldn’t have expected that the N4120 works so well with ZRAM. For work I am forced to use a recent mac with loads of RAM. When just browsing the web/checking emails I don’t feel any noticeable difference between the mac and the Stream for the CPU. (Of course, CPU/IO bound tasks are another story, and the display of the mac is in another league.) Usually I would consider myself to be quite sensitive to speed, I notice a real difference between using Gnome (with impatience etc. extensions) and Xfce, concerning the responsiveness of my desktop.
I’ll check the BIOS settings, I expect the same as you. Not sure, if I will lower the reserved RAM for the iGPU, everything works fine at the moment and I want to try some light gaming on this machine.