It sounds like there may be a Materials profile concept that I'm not using? That would get me closer to what I'm looking for; I'll look when I get home.
I still think it would be extremely useful to be able to save groups of related settings into their own profile, select zero to many profiles (I suppose these would be at the "user" level of the stack), and then reconcile conflicts then and there on the right side of the screen. I'm fairly certain the current "stack" implementation would not need many changes beyond making the top level user layer a collection, and extending the "settings" GUI to highlight settings with conflicts, then for the conflicted setting, allow users to select which profile's value to use, or enter another value. Seems like it could be implemented by adding another layer to the stack where selected profiles are pooled, and then compute them down to what is currently the user level so everything downstream can continue to work the same.
Above is the same as the example I gave with print speed. First, the trick would be to stop thinking in terms of having a single profile that defines all settings for the print. It probably doesn't make sense to store temperatures in a more generalized "Fine-Detail" profile, it's more likely this would be material specific (although it might be interesting to add a percentage change concept such that Fine-Detail could add 20% bed temp and take off 25% wall speed or something), but if the user did store it in both, and then the user selected two (or more) profiles that contained a value for the same setting, the user would need to reconcile the conflict... which doesn't have to be hard, show the user that the setting is in conflict in the list of settings (highlight it red and so on), show the values stored in the conflicting profiles (1 to Many, the user could select 5 profiles that all had print speed in them which would probably indicate poorly organized profiles), and allow the user to either checkbox the value from the profile they want, or simply enter their own value that would now be a more informed decision because they can see the range of values that were in the profiles they selected.
...as it is I find myself often trying to modify a profile that best matches what I'm trying to do, but switching between profiles to get values, writing them down, and hoping I don't forget anything (which I probably will) so I can go back the profile I'm trying to build and type them in... It's hard to believe I'm the only one. A big part of what I'm describing is really more about better handling and organization of saved settings. I recently found that I had been printing with a thin-wall setting (that would ignore tiny gaps) because it was accidentally saved in my base PLA profile for some print a while ago. ...if the workflow allowed user's to compartmentalize their settings into groups of settings that made sense together, not only would it be easier to get ready to print, it would be easier to notice odd settings as they wouldn't be in a nondescript wall of text, they would hopefully now appear in the list as color coded categories/groups of settings. You could possibly even allow experienced users to just leave all settings visible, because the ones you care about are at the top, color coded. ...and the ones you might care about don't have to be disabled until you go to another screen to make them appear on the list.