>>33729810There are more than one of most (presumably all) UBs. We can fight a trainer with Adhesive and then go to its Ultra Space and catch our own. We may also be able to go to Ultra Spaces of invading UBs and catch other ones there. Maybe if the invaders we saw aren't fought in the story (like Buzzwole/Pheromosa weren't), or if they are, you aren't allowed to catch them during the story. Or you can catch them, but you can just get more. Or even Ultra Spaces are version exclusive, so UB Burst invades in Sun and you go to the Ultra Space for Assembly, and vice versa in Moon.
To soon to tell.
