[Background]
We'd like to use Box Sign API to create a signature request by Sign template.
We want to use the existing template and replace the file to another file, but if we do so by Box API, the existing signature fields would disappear.
*This happens because there are no parameter in Box Sign API corresponding to "Keep Existing Fields" at Box Web.

[Request]
Please add a parameter to keep existing fields for Box Sign API when using an existing Box sign template.
*We think it's strange that what user can do in Box web is not possible with Box Sign API.