[MapProxy] Coverage for WMTS or grid?

[Lars-Daniel Weber]

Hi there!

While setting the coverage for a source, it's still possible to request tiles outside this coverage in WMTS. 
So I want to limit my WMTS by BBOX, but BBOX isn't accepted in services/wmts.

Then I tried to limit grids/webmercator by a BBOX, but this seems to change the internal calculation of the tiles.

Is it only possible to limit the coverage for a source?
It would be nice to get an error 404, 204 or similar. Right now, you're getting 200.

Best regards,
Lars-Daniel