It's actually another hoop for users:

- Safari + Kagi: you just need a default browser and a non-default search

- Orion + Kagi: you just need a non-default browser and a default search

- Firefox + Kagi: you need a non-default browser and a non-default search

It might not look that much difference but in terms of thousands users, any reduction for users' steps to do, it is better.