How to undo the upgrade to 1.1.1

[Festdewalkita]

@How to reflash the operating system on the Onefinity (Full SD card image)

There are times when you may have a file go corrupt or (advanced) users start poking under the hood and may need to reflash the entire vanilla image to the sd card. This process is essentially reinstalling the Onefinity operating system from scratch. This process is only for advanced users OR if you were directed to this via support.

I don’t think this reply answers the OPs undo question.

I have the same question, and this answer leaves me with the following:
Is this the only way to undo 1.1.1?
Is it essentially the only safe way to undo 1.1.1?
Is it possible to simply put 1.0.9 on a flash drive and use the upgrade methodology to “upgrade” back to 1.0.9?

I wish the 1F reply had elaborated a little rather than just re-posting information that was already available.