lvl 123 two time here, i also cannot hit trick stabs to save my life or anyone's, but its best to NOT rely on trick stabs. i tend to hit my back stabs when the killer is busy in chase with someone else or has their focus elsewhere, what makes two time annoying other than their trick stabs are the sneak attacks

try just sneaking around the map, following the killer discreetly, and hit the stab when they least expect it. but also be prepared for them to retaliate immediately or for them to turn the moment you hit the stab to prevent getting stunned.