Other than fit for human ...

Other than fit for human consumption, it's more of a quality decision.  I'd say carbon filtration to remove organics that can cause taste and odor issues is a good idea.  A stainless steel carbon tower that can be steam sanitized.  Other than that, does RO permeate make the product taste better, and is the money worth it?  Or, are you looking for consistency of product from location to location where source water can vary?  In that case, a single pass of RO would probably be sufficient to eliminate taste differences for most.