Cannot override Content-Type header for specific route

Hi ,
I have several files in my webservice which are gzipped and should have content encoding header gzip, but at the same time they have different content types (js, wasm). If override their content type in route-headers section in staticwebapp.config.json
it blindly ignores these changes and reset it to "application/gzip" in response header which leads to loading problems.
I also tried to specify mimeTypes sections but it ignores as well. There is only one solution which helped me to set header "x-content-type-options": "" . But it works not in all browsers.
It seems content type header somehow depends on encoding type, but it's very unclear how. Could you , please, explain how can I override content-types header for specific routes independently of encoding type.