Recommended approach for production discourse using PR (not merged)

Because you can create a plugin.

You do not know if they will ever accept your PR. And neither do I.

Here’s a hint: Someone from Team has responded in this topic and they didn’t say “Yeah, we’re pulling this in ASAP”. They instead gave you “Here’s what we do if we have a PR that won’t be accepted into core for months”.

It would appear that those are your choices.