Please see related Village Pump post here:
It explains the task and its context. Thanks. :)
At least the full functionality of the itwiki template could not be supported on outreachwiki atm as if I haven't missed something outreachwiki is not a WD client.
Thanks, @Base, for looking into it. I don't understand what a WD client is, but I take your word for it that this just won't work for that reason. :(
Declining this task per T247235. Feel free to reopen and assign to yourself if you plan to work on this - thanks!