One thing you could try, is to set a radius reduction percentage when selecting the new design pressure.
I just assumed that after changing the design pressure, that any number of heads would need to be repositioned or changed to a different nozzle. It's rare that changing design pressure is a "click it and done" sort of procedure.
But it's also something that helps for us to have the drawing, to see if we can come up with a better workflow. I would imagine that in dropping from an average of say 85% radii for 30psi heads, down to 25psi, that one would want the full 100% radius. As such, it's by design that the system restores the radius distance to 100% when changing pressure.
--J