It was getting very disconcerting on my Pi 3 1GB, with freezing occurring at frustratingly little system load (ostensibly) - like a couple of relatively heavy web-sites, or a canvas animation on-screen. I could just visualise the SD card being hammered for RAM, at about a millionth the speed.
ZRAM was a game-changer. Suddenly I could have 10 tabs open in a browser, rather than 4, and I never ran into freezing. I used the ‘More RAM’ installation in Pi-Apps. Have you seen that configuration?: