ESA, working at home and substantial risk

I've been looking at your latest version of the ESA guide (physical_wca_june_12.pdf) at the section on "substantial risk" where you say

Then you need to show that there would be a ‘substantial risk’ either to you or to someone else if you were found not to have limited capability for work.

...

How might this pose a ‘substantial risk’?

For example, might the exertion involved in travelling to interviews or going to work five days a week lead to a serious deterioration in your health condition?

(pp13-14)

I can prove that I can't travel to work more than one (unpredictable) day a week without serious risk to my health.

I was wondering how the "substantial risk" rule might be applied by a DM (or sceptical ATOS HCP looking at the form in the first place) to the prospect of working from home.

Standard answer on the "you could if you wanted to," boards is, "If you can use a telephone or a computer then you can work." "If you can post on B&W boards then you can work."

Does the DTP require you to account for the possibility of working from your home or even your bed? I'm not including the possibility of continuing with an existing employment from home, or part-time with your leg in traction. This is about being confined to your bed for most of most days by fatigue and pain, permanently.

P.S. Sorry if this is already answered elsewhere - I couldn't find a specific "work at home" topic.