Posting again since no replies on Discussion thread:
Mehter ability hotkeys are not remappable.
Malian hotkey for Produce Cattle is not remappable.
Mongol ‘Cycle’ through buildings of the same type (e.g. barracks) does not work when at least 1 is a ‘packed’ state. Furthermore, if you pack multiple buildings which are assigned to the same hotkey group and then unpack them again, the hotkey group disappears. Furthermore, if you have multiple types of buildings selected in their ‘packed’ state the hotkey/button to unpack disappears.