Haha you got ahead of me I will address that 
my solution is that Elixir Std Lib should support that out of the box (and it would also be nice to have GenServers forward callers via an option too). If you absolutely must have a solution, I wrote this library: https://hexdocs.pm/multiverses/Multiverses.DynamicSupervisor.html
Note that a Task.Supervisor is actually a DynamicSupervisor
