According to https://www.jsonrpc.org/specification#batch servers should accept batch requests from clients, which are an array of request objects.
The current API does not accept batch requests and returns an Invalid Request error.
I understand that this is not a high priority item.
Consider making use of my jsonrpc2 library which is strictly conforming to JSON RPC 2.0, very robust, and now supports use of context.Context in method functions.
https://github.com/AdamSLevy/jsonrpc2