Persistent Storage options with the standard version

According to documentation, I understand that the available persistent options include SQL Server, Redis, PostgresSQL, MongoDB and C1 CMS. Also, the documentation states that out of these Redis is supported with the Pro version Only. I just wanted to confirm if PostgresSQL, mongoDB, and C1 CMS are all supported with the standard (free) version of hangfire?

MongoDb is available as a 3rd party extension. So is C1 CMS. Only SQL Server is available as a ‘out of the box’-solution.

What does that mean?

That means all the other are more or less unsupported. They are updated at some time after hangfire is updated. And if you are lucky, they are not abandoned…
Here is the list of current storage engines:

I have experience with the MongoDB storage engine, and pretty sure I want be making that choice again. Unfortunately we were not able to switch to the pro package at the time and since we had all our data in mongo, it seemed convenient to have the hangfire data there as well. Problem was that the package was not kept up to date with mongo changes, so it held us back when new mongo versions was released. Back at the time there were major changes in the c# driver for mongo as well, which hit us quite hard at the time.

This is a couple of years ago. Pls listen to more recent experiences instead.