Disclaimer: I'm a maintainer but the next Dialyxir release makes a major improvement on this, thanks to contributions from Andrew Summers. He wrote a parser for the Erlangified term strings and uses the Elixir (1.6) pretty printer to print all the terms the way Elixir would. We're still fine-tuning the error messages and explanations but there is an RC on hex[0] - give it a spin if you haven't yet.
[0] https://hex.pm/packages/dialyxir/1.0.0-rc.3