I have a 5500 W RIMS and I can "step" the mash temp just fine. The caveat is that I can only do it in all or almost all barley batches. When I use 30% or more rye or wheat I have scorching issues.
I totally disagree about the low flow rates. When you're trying to increase the temp significantly you the fastest flow rate possible without sticking the mash to keep conducting heat away from the element. This will not only help to prevent scorching, but it's also going to provide the fastest heat transfer. It maintains the highest dT between the fluid and the heater, which will hasten heat transfer.
The power to tax, once conceded, has no limits; it contains until it destroys. I was not joking when I told them to dig into their own pouches. It may not be possible to do away with government — sometimes I think that government is an inescapable disease of human beings. But it may be possible to keep it small and starved and inoffensive — and can you think of a better way than by requiring the governors themselves to pay the costs of their antisocial hobby?
R. A. Heinlein