When the 1,00x Scale is chosen, no upscaling is performed, therefore it would be logical to display ‘None’ instead of the currently displayed 1st model in the list. Similarly, it would make sense to change the ‘Upscale’ button’s label to ‘Refine’ upon user selecting the 1,00x Scale.
Kind of disagree on changing the model selection, I think it's fine. UI options the user has specifically selected don't typically change even if they're not used in an operation.
When the 1,00x Scale is chosen, no upscaling is performed, therefore it would be logical to display ‘None’ instead of the currently displayed 1st model in the list. Similarly, it would make sense to change the ‘Upscale’ button’s label to ‘Refine’ upon user selecting the 1,00x Scale.