dbx DJdi Centre Tapped transformer

I'd like your thoughts on this:
Just picked up a dbx DJdi box (Two Channel transformer Isolated Passive  Direct Box).
One of those -"might be useful so put in a lowish ebay bid" purchases.
So opening it up to take a look: pretty much as expected : Input attenuator pot; Ground Lift switch (simple connected / disconnected - ie no resistor / capacitor / diode combo or anything) and two smallish transformers.
But...noticed that the secondary (ie low Z output to XLR) side of the transformers have two windings that are joined in series via the pcb.
Nothing unusual in that but the junction of the two windings is taken to the output ground / Pin 1 ie a 'centre tap'.
The two output grounds are separate but the input ground connections are common (and connected to metal enclosure chassis) so that if the Ground Lift is Off then the Pin 1s are connected together and to the Input Ground.

I don't really understand what benefit the 'centre tap' on the output windings would give over a floating output. The following input stage should perform any referencing to '0V' whether it is balanced / unbalanced ?
I'm used to active balanced configurations etc but not quite so much transformer stuff so wondering if I am missing anything with this design ?

Newmarket said:

noticed that the secondary (ie low Z output to XLR) side of the transformers have two windings that are joined in series via the pcb.
Nothing unusual in that but the junction of the two windings is taken to the output ground / Pin 1 ie a 'centre tap'.
The two output grounds are separate but the input ground connections are common (and connected to metal enclosure chassis) so that if the Ground Lift is Off then the Pin 1s are connected together and to the Input Ground.

I don't really understand what benefit the 'centre tap' on the output windings would give over a floating output.

Click to expand...

Neither do I. I certainly can see disadvantages, such as issues when connected to a phantom-powered input. DC current in xfmrs is never a good idea, even if there is no risks of frying them.
Such an arrangement does not work with unbalanced inputs; although XLR inputs are supposed to be balanced, you never know what surprizes are in store when dealing with DJ equipment.
I would disconnect this center tap altogether and enjoy the benefits of a floating connection.
The only explanations I have for this quirky design are:

• The designer is an eejit
  
• The designer tried to mitigate the effects of primary-to-secondary capacitance, by dumping HF contents to ground. A much better solution is adding two ceramic capacitors on the XLR. These units are so cheaply made the cost of two ceramic capacitors may have been deemed a sumptuary expense.

Thanks for the (balanced) input
Being an electronics design engineer I'm reluctant to criticise other people's designs.
But I might just cut the connections from the transformers to the Pin 1s.