It's a free text field. There is no dedicated logic.
few things I've used before:
Can just be a char-delimited string. e.g.
pipe | : "path=xyz|debugmode=false"
string split it in code; could even map it to a custom settings object.
When adding more complexity you could also add a json-string and use a lib to parse that to a custom settings object. Downside is that the editing of the json object might be harder for non-techs.
https://stackoverflow.com/questions/9988395/how-to-map-json-to-c-sharp-objects
You could also just create a custom settings block for this import. This way you could use the default controls for path selection, drop down lists... etc. pro of this approach is that you can add specific validation and can be sure the settings are there.
https://docs.kentico.com/k12/custom-development/creating-custom-modules/adding-custom-website-settings
what ever approach you use make sure to add enough validation in code and don't make any assumptions on values or settings being present. Either cancel the task with an error message or make sure to add default values.