This DAC does have such bypasses (C29, C30). Here's one whole channel's I/V stage. On the right edge of the photo it enters the 2nd voltage follower stage
We call it an I/V stage (Current -> Voltage) but it could easily be called a double transimpedance amplifier layout. The sections in orange are your two feedback resistors (one for each opposed leg of the L channel signal; R9 and R18). Feedback sets the conversion ratio of the I/V stage. In dark green you have 'Filter' generically. To the right of the output, it is
a high pass filter. (Electrolyte + R2 and electrolyte + R37) This will remove the DC from the signal. If you plug in the C and R values (1000R 100uF) then you will see that any 'signal' below 1.5Hz will be cut out. Since DC looks like a 0-Hz AC signal, it is removed at this stage.
The bits in green next to the amplifiers (R19 + C2 and R20 + C8) are part of the feedback network and sets the maximum frequency operating point of the opamp. Any frequency above that pole/pole will have a decreasing amplification. You can think of it as a sort of low pass filter. Usually these values are set to be in the low-MHz range.
The non-inverting input of the opamp is tied to AVCC/2. That value is obtained by a simple voltage divider formed by R136 and R135. This is our virtual ground a.k.a. Vg. So why this value? THe datasheet has the answer.
We need to set the current mode output offset to 0 so that at idle the DAC is not sinking or sourcing current. Since the equation for current offset uses Vocm, the easiest way to ensure that happens is to set Vg = Vocm. That way we have 1000* 0 / Rdac = 0mA.
If you want max performance from your downstream devices, it is best to set the gain to max as near the DAC as possible. THe 2nd stage of the opamp stack is a voltage follower, so it has unity gain (a.k.a voltage in = voltage out). For standard XLR connections, you want about 4Vrms between both pins, or 2Vrms per hot or cold pin. This is about 5.658Vpp on either side of the opamp. Each 'leg' of the signal can put out a max of 7.7mA, and the I/V stage ratio is just a simple current across feedback resistor determines voltage. So Fb resistor value * current = Vpp. We know Vpp and we know current, so an ideal resistor value for best gain staging for optimal SNR would be about 730-Ohm.
This should give ~5.65Vpp on each leg (XLR+ and XLR-) which would combine to be 11.3Vpp across both which is 3.995Vrms. But the Leaf is set up so that RCA does not apply any gain/cut. So if you plan to use XLR then the resistor swap might be worth it (though maybe the improved SNR would not be audible). If you plan to use RCA then the factory supplied 390-Ohm resistors are about right.