Is there any way to upload a specific/older AP image/firmware version in CnMaestro ( let's say 3.4.x for example) and make a software update job from the platform in order to downgrade the firmware of several APs at the same time from CnMaestro? ( so, no need to do the downgrade manually accessing via GUI to each AP)
If you are running an On-Premises deployment you should be able to upload packages from the support download page and upload them to cnMaestro via the Applications > Server > Software Images page. Older versions of software images can be found in the Archive tab of the download page. I believe the file needed are the ones in .tar.gz format.