How to mass upgrade ac radios to 5.9.1 from CnMaestro?

We are in the midst of upgrading some of our 3K sectors to 4500’s, how do we automate the upgrade to 5.9.1 on CPE that is running 4.7 (for example). It seems 5.9.1 is considered AX firmware in CnMaestro so when I schedule an upgrade for the CPE it just fails saying "
The software image is not available to download!"

I can update the CPE manually by logging into them, but the idea is to not have to do this hundreds of times

Are you using cnMaestro cloud or on-premise?

cnMaestro on-premise

You need to grab the AC and N images from Cambium Downloads and load them into cnMaestro on-premise. Try this first.

If your version of cnMaestro on-premise is older then the release date of the firmware, you will most likely need to update it in order for the radio firmware updates to work correctly.

What is the most recent version of on-Premise cnMaestro?
I was certain that was at least a few years ago, which would make them useless for any modern gear.

If I’m mistaken, I’d love to use this feature again.

https://support.cambiumnetworks.com/files/cnmaestro/
The latest is 5.2.0-r3 OVA / 2025-02-27

Does this release include the requirement to sign up for any kind of off-premises cloud service?
I want to keep absolutely everything in-house, and to my knowledge later version of cnMaestro has some form or another of cloud requirements.