I think this is dominance. When should I intervene and what do I do?

For the most part these two are good at playing together. They don't cuddle, but they'll sleep near each other, or on their (separate) favourite spots around the house. Gray is Aske, 1yr+ got him in May, white is Alva, 7mo got her in early Dec. Introduction went pretty fast, I think it took a week of separation with feedings on either side of a door before they seemed to accept each other's presence. Alva is deaf, but she's feisty and will chase him as much as he chases her. He is a bit obsessed with her, where she is he follows. I play with them and they seem ok at sharing the string toy I wave around. Alva gets a little wild with it and eventually Akse will want to stalk/jump her rather than the toy.

I would love it if they became BFFs but I would settle for good company for each other. Do I need to be more vigilant about Aske's dominance? I worry that Alva gets annoyed/harassed by him.

Advice is super welcome 🙇🏻‍♀️♥️

P.S. Sorry for my weird audio, I had just woken up and was still half unconscious 😅