Isolate each leg, fix the imbalance.
Keep your hips planted and don't let the knee cave inward as you press.
One foot centred on the platform means one set of quads drives the entire load, with the glute assisting out of the deep knee bend, and the machine handles all the balance. That combination is the point, you get honest single-leg strength work without the wobble of lunges or split squats. It is the cleanest way to find and fix a leg imbalance while still moving respectable weight.
Different tools. Lunges add balance and coordination demands, the single leg press strips those away so pure leg strength is the only variable. If wobble ends your lunge sets before your legs are actually tired, this machine is the answer.
More than half of your two-leg number is normal eventually, but start well below that. One leg pressing alone recruits differently, and the first sessions are about owning the range and keeping the knee tracking straight.
Centred is the default, as if the platform were built for one foot. Slightly higher shifts work toward the glute, slightly lower biases the quad, but keep the whole foot pressing and the heel down wherever you place it.
