I was always on the edge of tripping myself into crashes, had increasing amouts of sick leave, ignored the signals to stop far too often, and had no success in getting my colleagues and bosses to understand my limitations.
As a member of a staff of maths and science lecturers, if I'd had data to demonstrate my difficulties and what was triggering crashes, I think they would have been interested in helping me interpret the data, instead of being skeptical about my needs.
Yes, good points.
I had the same problems, but in my case it would have been counterproductive to have data. The cause of the crashes was that I was working, and there were a handful of periods when I wasn't really up to it. We could only take six months' sick leave on full pay, and as half pay wasn't enough to live on, I had to go back even if I wasn't really ready. The only options were to stop work altogether (probably for good), get myself evicted because I wasn't earning enough to pay my way, or conceal some of the toll it took on me.
I could hide it to some extent because I stayed in admin-heavy jobs for a long time and got very good at them. I streamlined or automated processes, shifted workload around to accommodate periods of low function, and traded job roles with colleagues. Despite the illness, I think I was an asset to my employers for 38 of the 40 years I worked; the other two, I was underperforming because I was still emerging from one of my crashes.
I can see the benefits of data, but there are significant risks if disabled people share it with employers. For those in jobs with schemes offering ill-health retirement, the evidence could be really helpful if they needed to make a case for medical retirement. It might even mean they could get it before they drove themselves into severe illness.
But the majority of workers don't have that kind of security. For them, data on how a disability affects them could quickly turn into a hard (and overly crude) measure of capacity that would make it easier to sack them, even if they were only experiencing a temporary dip in their performance. Plenty of healthy employees have those dips over a working life—bereavement, new parenthood, medical treatment—because people aren't machines. But their employers won't have movement data they could weaponise to get rid of them.