No-no, le9 is very useful both with swap (physical or zram) and without. With zram it makes swapping process seamless (no lags when swapping), with physical swap on HDD it makes it a bit softer (on regular kernel both swapping and file reloading upon swapping occurs, making the process even more slower; with le9 it's mostly only swapping), and without swap it prevents hard thrashing and freeze of the PC, (additionally) making OOM killer to trigger much earlier than it usually triggers.