Interesting! Actually, the leverage flag is set in AssetsZ9.csv, so one can at least back-test Z9 with any amount of leveraging. I tried x6 and the shape of the equity curve just got multiplied (got congruently higher), which suggests that higher leverage is fine with it!

With IB, does one set the AssetsZ9.csv flag to 4 and that automatically performs all trades leveraged 4 times, or does one have to set this property somehow on the broker platform?