MapProxy can be configured to use a WMTS as a source
MapProxy config
The test MapProxy instance is configured via D:\mapproxytest\mapproxy.yaml and available in a local browser on the server via http://localhost:84/ and http://localhost:81/iShareGISTEST.WebLocal/mapproxy/ (via a Rewrite rule). The test instance has the MapProxy demo available at http://localhost:84/demo/.
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