That is frustrating. Do you think you could “hack” your own version that sits on your normal desk? Something like this with some kind of platform (like a ream or two of printer paper or a thick book) so your keyboard would be at the right height?
I’m thinking that something minimal that packs easy/takes up a small footprint on your desk might be worth a shot?
Maybe worth it to try getting a doctors note as well if your employer is still inflexible about you rigging your own setup on your desk?