Sure, the Command can be recreated from scratch, there are workarounds for this issue. Implementing 'Clone' would do the job too.
The point here is that 'Command' is already a builder and can be used for multiple instances with one of the execution triggering methods. The other attributes (Oops as I am writing this I haven't checked for Stdio) do have API's to refine them before firing one execution again, only the 'args' does not. I'd call this an inconsistency in the API.
IMO it would be valuable to add this, to my understanding it won't cost much and won't break anything, just making things more consistent and easier to use.