For eWON Flexy and Cosy 131 and since firmware version 11.0, it is no more required to perform an eWON recovery to upgrade to a major firmware version. This major version update can be performed with a simple eWON firmware update thanks to “Pivot firmwares”.
This means that the firmware can also be updated from remote.
By "pivot firmware", we define firmware versions that are mandatory to upgrade to before going any higher.
For example: if the firmware version is currently 11.2s2 and there's a wish to upgrade to v13, a first upgrade to v12 is required. Once the current firmware version is 12, then only can the upgrade to v13 be operated.
The pivot firmware is in fact all major versions. This means that firmware v12.0s0, v13.0s0, ..., v20.0s0, ... are all pivot versions. And so, to upgrade from v12 to v15, the firmware will first need to be upgraded to v13, than to v14 and finally to v15.
Be aware that a firmware recovery is still possible. If you have a local access to the eWON, then it is easier to perform directly an eWON recovery.
Therefore you do not need to step through all different pivot firmwares. Using recovery allows you to jump directly to the latest firmware version.