proxies.json to "Azure API Management" in v4 migration guide? Local execution?

I found [this statement that Azure Functions v4 doesn't support proxies.json](https://docs.microsoft.com/en-us/azure/azure-functions/functions-versions?tabs=in-process%2Cv4&pivots=programming-language-csharp#runtime). Is there an explanation for this change? Is there a migration guide to Azure API Management? Is there a way to run the Azure API Management locally for apps that require the proxy behavior to operate correctly?

I see there is some idea of automatic migration [Import an Azure Function App as an API in Azure API Management](https://docs.microsoft.com/en-us/azure/api-management/import-function-app-as-api) but I'm weary of even experimenting with changes to even the Dev environment of my Terraform-managed app for fear of corrupting it (could it be 100% undone after collecting the auto-migrated configurations?)

Here is a representation of the various proxies.json features I currently use. Default document, many-to-one resolution, wildcards, external routing, environment variable injection, query parameter passthrough. API Management can do these, and emulate them on the local developer machine?

```
{
"$schema": "http://json.schemastore.org/proxies",
"proxies": {
"public-default": {
"matchCondition": {
"route": "/"
},
"backendUri": "http://localhost/api/assets/index.html"
},
"public-index": {
"matchCondition": {
"route": "/index.html"
},
"backendUri": "http://localhost/api/assets/index.html"
},
"other_assets": {
"matchCondition": {
"route": "/assets/{*any}"
},
"backendUri": "http://localhost/api/assets/other/{any}"
},
"third_party": {
"matchCondition": {
"methods": [ "GET" ],
"route": "/example/third_party"
},
"backendUri": "https://www.example.com?auth=%example_license_key%&query={request.querystring.query}"
}
}
}
```