[MapProxy] WMTS image format ignored

[Anne Blankert]

Hello list,

Is it possible to get WMTS to fully support both jpg and png as image 
format in a single layer and have these formats exposed through the WMTS 
capabilities?

I have created both a png cache and a jpg cache, but if I define in the 
yaml:

layers:
   - name: layername
     title: layer title
     sources: [layer_cache_png, layer_cache_jpg]

The layer 'layername' no longer shows up in the demo. If I request the 
layer directly, I get 'internal error'.

Thanks,

Anne