That does seem a bit bizarre. With that there, I'd doubt if you end up with any lubrication at the head, as the the pressure is going to be severly limited before it even reaches the metering units at the head.
I wonder if somebody has previously been at it, and swapped a straight through fitting for a metering unit?

You didn't happen to order any spare FJB2s?
I could do with one more, but I'd rather avoid paying more for postage than the unit!