How much shed at 3 weeks? Technically, all that hair at 10 weeks should have been new hair and it wouldn’t look like much less hair at that point yet (unless you didn’t wait long enough for all the new hair to come in). Basically, you can’t judge reduction at that point yet.
We can’t recommend settings over the internet like this. The tech should test what the highest joules, largest spot size, and lowest pulse width your skin can handle safely. We can’t know that. Everyone’s skin is different and skin types are approximate.