Pirates
Luckily for Khan, Major General Arngan was the last arrival that demanded his presence. Alexander, Prince Thomas, Princess Rebecca, Abraham, and the other members of his inner circle could handle everyone else. Garret Bizelli joined the lab as promised, but Khan didn't show himself at his landing.
Other prominent figures flew through Baoway, but Khan ignored them, too. Only Lord Rsi or people with similar relevance could make him appear, but nothing close arrived on the planet, allowing him to focus on his training.
Khan's isolation didn't imply a lack of curiosity. He cared deeply about many aspects of the planet, especially those connected to his friends. However, he had his priorities straight. He knew everything he had built came from his superiority, so he had to hammer down that quality until no one could hope to match him.