Feature Request:Signed urls with parameters for external tools

At present, external tools use mechanism of signed urls by defining urls needed in external tools in "allowedApiCalls" in manifest json of external tool. But it does not allow use of parameters that depends on user choice (interaction) with external tool. For example, if user wants to work with specific variable of tabular file, and dataaccess subset api is needed for that, for example http://localhost:8080/api/access/datafile/6?format=subset&variables=123 At present the only option is use http://localhost:8080/api/access/datafile/6 that for large tabular files slows down the application (external tool)
It would be useful to have a mechanism of defining parameters in allowedApiCalls urls based on information that would be passed from external tool.

Start by tracing how external-tool manifest.json entries in allowedApiCalls are processed and how signed URLs are generated. Define the parameter-passing constraints and verify that a user-selected value can produce a signed URL for a request such as the subset data access example without weakening authorization.