The answer is no. I messed up by going too fast at the start, and then needed to pee badly enough that I had to slow. Oh well. Unofficial time of 28:16 will do.
Putting any such solutions into place would cost money which the tories don't want to spend though because they'll have given all their friends nice tax breaks instead.
There will be a sweet spot for efficiency. Below a certain point and the PSU might be wasting energy to keep stable. Above a certain point and efficiency tails off as things heat up and reach limits. Somewhere in the middle, the supply is nice and stable, well within limits.