With a character like Beldaruit, a disabled man who uses illusion magic, it would be very easy and even typical in a story like this for his smoke sculptures of himself to be him walking around on his own two legs, and his disability being a 'reveal' that explains why he is the way he is. (Hell, we even know that smoke sculptures CAN be altered from what they're a reflection of, because of pixie coco).
Instead, witch hat makes it clear Beldaruit views his disability as an important part of his identity, by including his chair as part of his appearance even when hes not Actually There. I think it speaks to Shirahama's understanding of disability that she gets most chair users don't view it as 'shameful' but rather just a part of their body like any other.
