Hi All

Where can the above parameters be set please?

"The amount of simplification (called the threshold) depends on the size of the selection. Therefore, if you select a path along with some larger object, it will be simplified more aggressively than if you select that path alone. Moreover, the Simplify command is accelerated. This means that if you press Ctrl+L several times in quick succession (so that the calls are within 0.5 sec from each other), the threshold is increased on each call. (If you do another Simplify after a pause, the threshold is back to its default value.) By making use of the acceleration, it is easy to apply the exact amount of simplification you need for each case."https://inkscape.org/doc/tutorials/advanced/tutorial-advanced.html

Maybe here:

Many thanks Tyler.

However I was aware of this setting I assumed it does not have effect on the aggressivity and acceleration.

It does have.