If it's even possible to utilise your dreams usefully... surely this will have an impact on sleep quality? You can't just not rest and expect to get the benefit of rest.
I've used lucid dreaming to solve problems in the past. It's not really that different from trying to solve problems while on mind altering substance. You get a mix of brilliant solitons you'd never think of any other time and complete nonsense.
There's also a lot you just forget. I don't know if it would be helpful to recover that stuff or not. It may just feel important or correct without actually being useful in any way.
It doesn't negatively impact sleeping for enjoyable things like designing. I can't imagine it would be useful for anything you don't actually want to do.
But then again, extracting value isn't really the point of a lot of work. Most of it is about power and control. The work place is basically non-consentual BDSM, so it would make sense for an employer to demand someone works while sleeping just to show that they can exercise power over them.
I'm trying not to be too negative here, but have you seen the innumerable graphs/charts that show the productivity increase vs. wage stagnation, etc.? Hard not to see how this would be abused immediately for corporate -profit$- instead of benefiting the workers.
I've seen them, but I was just trying to get away from the constant doom posting for a while and think how nice it'd be to be able to be done with work right away when you wake up.