Ok this is what I did:
Use the OTA firmware upgrade method:
Download the firmware OTA update package (currently 0.4.1) (full OTA and in zip format) and place it on a USB flash drive (FAT32 and MBR needed).
https://ugoos.com/downloads
Insert the USB drive into the AM6B+, hold the recovery button and insert the power-plug. Hold recovery button for 5-10 seconds.
In the recovery menu, choose “update from ext” and select the update zip file from the USB drive.
Remember to back up your data before re-flashing, as this process will erase all user data and settings on the device.
After recovery is done, go through checking for updates and reboot cycle until it is on latest version (currently 0.5.4).
Here I verified that the included remote now works for powering both on and off!
It did not work for power-on, only power-off previously!
I also made sure while booted into Android, that Auto Power On is disabled: “Device Settings” > “Power” > “Disable Auto Power On”.
Now follow installation guide as usual:
But skip the remote.conf, since we will use IR with MCE.
After booted into CoreELEC, enable SSH and run the command “ceemmc -x”.
Reboot without external USB inserted.
Setup Harmony Remote:
In Harmony for the device, I use ‘Microsoft Media Extender’.
It is setup with changed settings for the device to “repeats" and “inter-device delays” to 0 for both.
Added the “hdmi_cec=‘0’” to the “HDMI CEC OSD Name” section:
# mount -o remount,rw /flash
# vi /flash/config.ini
Added the keymap.xml file to /storage/.kodi/userdata/keymaps folder.
For the “make sure ALL CEC stuff is turned off/disabled in Kodi and CoreElec settings” step, in KODI I went to “Settings” > “System” > “Input” > “Peripherals” > “Status: Disabled”.
Disabled all items to get it to state Disabled.
Rebooted into Android.
In Ugoos Android, I went to “Settings” > “Device Preferences” > “Display” > “HDMI CEC” > “CEC Control” to Off.
Then restarted back to KODI.
Power-off works, but not Power-on.
Implemented workaround, in Android there is an option to add a secondary IR-code to power-on (Needs to be NEC compliant IR code).
“Settings” > “Device Preferences” > “Power” > “Additional IR power-on button”. Here I added power-on from an HDMI-switch I no longer use (Amazon.com).
I then configured Harmony to have 2 different buttons for the ‘Microsoft Media Extender’ Device. One is the current default for Power-off, and then the new code learned from the HDMI-switch remote for the Power-on.
Now both power-off and Power-on works with the Harmony MCE remote! Suspend also work.
Then configured from recommendations, with my own tweaks:
Add plugins.
Done!