Why the difference between lang/elixir and lang/elixir-devel? (also: elixir-devel doesn't support mix release)

From: Pat Maddox <pat_at_patmaddox.com>
Date: Tue, 10 May 2022 04:12:56 UTC
I had been working on a patch to lang/elixir-devel to support mix 
releases, per the problem I shared in 

When working on it, I saw that lang/elixir doesn’t have the problem - 
it doesn’t patch `elixir` to “hard-wire” the OTP release. So I can 
just depend on lang/elixir instead.

I had assumed that lang/elixir-devel just provided a more up-to-date 
version of elixir, to get access to a newer elixir while still using 
quarterly ports.

That appears not to be the case. Two key differences I note are:

1. lang/elixir depends on lang/erlang, whereas lang/elixir-devel depends 
on lang/erlang-runtime*
2. lang/elixir builds elixir as-is, whereas lang/elixir-devel patches 
the `elixir` script to “hard-wire” the OTP release.

What is the intent of the lang/elixir-devel port?