UCLCWRA and workstations

I use a wheelchair when leaving home (with assistance). My UCLCWRA form asked how long I could be at a workstation with a straight backed chair. I put 45 mins as that seemed correct at the time, but when in the wheelchair recently I wondered if I am incorrect if I can manage longer than that in my wheelchair? (I do have to rest after and lay down and am impacted). Have I got my answer wrong please? Thank you.