Thats what ive done compared the two , the modified as shown in the images above and the original state and asking why you need to modify a preset to change settings like support or add a brim rather than save a file
The comparison in your initial post showed identical presets - not a modified one.
The comparison tool only works with saved presets.
I think you downloaded a .3mf file project file from MW, not a preset. It loaded the settings the model creator used for a successful print. They used the 0.16mm High Quality @BBL A1 system preset, with at least one modified setting (as indicated by the asterisk and circular reset arrow). Those process modifications are stored individually in the project, but not as a complete new preset. If there were a new preset, or a preset in a project, it would have a different name and no asterisk. If you hit the red circular arrow you will reload all the original preset values. The easiest way to find the individual modifications would be to look for the red labels and reset arrows.
I find it helps me be aware of what might be changed if, in Preferences, I uncheck the “Automatic transfer modified value” and “Clear my choice” for everything. That increases the prompts I have to answer, but makes me more aware of possible changes, and I can decide if the changes will be acceptable.
That was the point of the original question , the newest file shows a change/mod but the actual presets are the same , apart from the support and the brim , if i hadnt sliced the plates first , i probably wouldnt of known the difference , i tend to accept them for what they are modifications to a model being recirculated. sometimes it helps to know these things
I am not sure if I am misunderstanding the question or if I am not providing a proper explanation.
Your top picture shows that a System Process preset was chosen and then the red tab labels show that modifications were made in the Strength, Support, and Others sections. Those changes to the Process settings will be saved when the project is saved, but will not change the System preset. You cannot save permanent changes to a System preset.
So it is to be expected that as soon as the preset is back to its original state, all the changes are gone.
You can see where the individual changes were made by selecting each tab highlighted in red and then looking for settings with red labels. To see what changes were made, save the settings as a preset (with a different name) and then use the Compare tool, selecting the System preset and the User preset. The tool compares only saved presets, it will not compare a preset to the current Process settings.