ENBoost + iVSyncPresentInterval = 0 vs without ENBoost and iVSyncPresentInterval = 1

PS. 900p max settings, except no AA

ofc with ENBoost, the VSYNC is also enabled because:

enblocal.ini
[ENGINE]
ForceVSync=true

a lot of enblocal.ini with VideoMemorySizeMb for probably 90-95% cases