I think Speedrunner would probably give him a hoodie, headphones/earbuds, or turn the office chair into a gamer chair much to Asterion's displeasure. I could see him trying to convince people Asterion is a vtuber alt now that he's been learning about cameras. Definitely needs to try an energy drink/G-fuel knockoff at some point.
I'd personally enjoy more collared shirts that show off his armband. So far I think Kota's restaurant is the only one that does, and I much prefer the atmosphere of Luke's lounge so I'd want an option on his route, too.