The sheet parameters thing is a neat idea, but directly changing the value of a component is kind of gross. Half of the point of using a tool like Altium is to maintain consistency from the library, through the design, and into your manufacturing/documentation outputs, and changing the component value locally instead of selecting a different part from the library breaks that process. It's also a fairly hidden way of making the component change, and could easily cause problems if someone who doesn't know it's there edits the schematic later on.
The best solution is probably to use assembly variants. You can define a single 'standard' variant as and then once the design is compiled, open the sheet in question, and at the bottom you'll see a tab for each of the instances of the sheet in the project. You can easily select which instance you want to edit, then right click a part -> Variants -> set the alternate part for the Variant. You will need to make sure that the new variant is selected for all of your outputs! Otherwise everything will show up as whatever non-variant default is.