This question is applicable to project management as it is in all other types of operations, whether it is knowledge type work or labor. The application of the science is through generalization of the findings versus a study that shows a direct correlation between a project optimized ergonomically and one that is not.
The challenge in answering this question is setting expectations that you do not have a cause and effect between an egonomic station and cost, schedule, and scope performance. There are an infinite number of variables, including a host of uncontrollable, random variables, that ultimately affect where we end up with cost and schedule and scope quality. Our jobs as project managers, and operations managers for that matter, are to increase the likelihood of favorable results by pulling the levers and pushing the buttons that are known to help with the full understanding that you still have risk of poor performance and complete failure.
Googling ergonomics and performance yields a host of scientific findings that suggest improved musculoskeletal and visual performance via lack of symptoms or employee complaint. One could easily conclude that, in most cases for much of the time, performance should be improved by providing ergnomic work stations.
Personally, I do not think there is much debate around this topic so I would certainly include an ergonomic work station and environment, and the cost thereof, in my project planning. While the results are no where guaranteed, no magic bullet, these are the right levers to pull to help increase my odds.
Health and Performance Consequences of Office Ergonomic Interventions Among Computer Workers, Michelle Robertson
Office ergonomics training and a sit-stand workstation: effects on musculoskeletal and visual symptoms and performance of office workers. Robertson MM, Ciriello VM, Garabet AM.
The abstracts are available online; however, you might have to pay to see the entire study.