Use specific tile levels when cascading tile service as WMS in MapProxy

When cascading a tile service through MapProxy to provide a WMS service is it possible to restrict the zoom levels the source tiles are pulled from?

The original tile service I’m using uses different imagery sources at different zoom levels e.g. when zoomed out clouds and older imagery are shown, but as you zoom in to higher resolution imagery the clouds are lost and imagery is more recent.

Ideally I’d like to restrict the zoom levels used from the source tiles and have MapProxy stitch tiles together to provide the WMS service imagery at different resolutions, providing consistent imagery no matter the resolution viewed. Is this possible and are there any configuration examples I can use as reference?