Just read your pm and saw this notice on the board.
I am not a SQ4 ownwer but if you are sure the cranks have been as a pair I think there's no need to balance .....
however, over here in Holland is Herman Noort who has been very involved in getting these rods production ready.
He has them in his MkI.
Although he has not done much milage yet due to gearbox trouble, he will be able to tell you all about it.
Also in Amstelveen there lives Charles Qua, he also knows a lot about SQ4's.