You got me interested in solving this one, as I too should have tendered and change due on receipts as that's what a customer expects to see.
So I set it up earlier to test it, and we were on the money.
Reset TENDERED & CHANGE DUE on CREATE TICKET .
On CHANGE AMOUNT UPDATED Rule set TENDERED and CHANGE DUE to TenderedAmount & ChangeAmount
Then check TENDERED on PAYMENT RECEIVED and if 0, set TENDERED to AMOUNT
Plus the 2 Actions for updating Tendered & ChangeDue
With the Pole Display I didn't need the first or third settings.
Simple now
Splitting checks is not popular in Oz (in fact its discouraged), this feature just helps the operator think quicker. The receipts print the same after the first amount is paid, no matter what else gets tendered. My solution would be if the bill is split evenly, then take the first amount, hit Print Receipt x3 and take the remaining money.
I tried some Rules to update Tendered, but wasn't successful.
Maybe Emre can clarify this, as I am sure it will come up elsewhere.