I think Liam and Bacon would be great friends. Because he works in a daycare, Liam would definitely have the skills and patience to deal with Bacon, since they’re mentally still a kid even in step 2. Also, I could even see him following Liam around like a puppy.
Kathryne is a bit trickier. It’s not that she isn’t friendly, but has a hard time trusting people and doesn’t open up at all unless she gets to know you well. I feel like they could be friends but Liam would definitely have to work for it. I think that KitKat would get to know Liam through Bacon but from there it could go one of two ways, either they’d also become friends by both hanging around Bacon or KitKat would let the two boys be and remain more neutral.