Also note that there is considerable variation between nuclear plants,so even if your (to me, dubious) claim of French operation is correct, then there is no implication that follows for German plants designed to different specifications.

The point, again, is that a complex piece of machinery designed under a certain set of assumptions about operation regime cannot be assumed to be reliable under a widely different regime because an abstract class of equipment, e.g. boilers, can, in theory, be operated differently.

As just one consideration, the training and staffing of equipment operators under the assumption of load following is not going to be close to the existing training and staffing.