What's a free proxy for the specific purpose of free Usenet posts?

Q: Does a free proxy even exist to post using free nntp news servers?

Advice for beginners in getting up to speed in minutes on VPN was posted
this morning where the question then came up of a "free Usenet proxy".
o How to get up & running on a free public vpn service in minutes
https://groups.google.com/forum/#!topic/comp.mobile.android/Bv8bwG4ggnc

Mike Easter, always being purposefully helpful, suggested another POV:
https://groups.google.com/d/msg/comp.mobile.android/Bv8bwG4ggnc/lcJ5Jo8OEgAJ

Specifically, Mike referred to this helpful article saying not to use a
public VPN service as a "glorified proxy"
o Don't use VPN services.
https://gist.github.com/joepie91/5a9909939e6ce7d09e29

The article Mike kindly referred to suggests using a "specific proxy" instead:
https://groups.google.com/d/msg/comp.mobile.android/Bv8bwG4ggnc/oAPYdk4QEgAJ

That's all well & good if you're posting to Usenet via a browser:
o TBB https://www.torproject.org/projects/torbrowser.html.en
o Opera VPN Browser https://www.opera.com/computer/features/free-vpn
o Epic Privacy Browser https://www.epicbrowser.com/
etc.

There's nothing wrong with the alternative POV of that article other than
the unanswered question, which is the question asked in this thread.

What proxy answers the specific problem set is of finding a reasonably fast
& reliable free proxy that allows the user to post to free news servers?

In summary, for _any_ common consumer platform (Win/Linux/Mac/iOS/Android):
Q: Does a free proxy even exist to post using free nntp news servers?