This figure is not specified.

I found,
lowest to highest Ref. Level,
highest values found for each channel:

ADI-2/4 Pro SE:

XLR differential: 0.00004 to 0.00068 V
XLR hot or cold to GND: 0.00015 to 0.00038 V

Rear TRS to 1/2: 0.00013 to 0.00057 V
Rear TRS to 3/4: 0.0004 to 0.00375 V

ADI-2 Pro 1st Gen:

XLR differential: 0.00020 to 0.00081 V
XLR hot or cold to GND: 0.00025 to 0.00056 V

Rear TRS: 0.00016 to 0.00041 V

Using a typical DC coupled power amp with 32 dB gain / x40 amplification factor, most would stay below 0.030 V at the speaker.

My worst case 0.00375 V would result in 0.15 V DC, or 0.006 W DC Power into a 4 Ohm speaker.

Just as a reference: the resulting (theoretical) peak audio power when running music at this setting would be 19000 W!

Most power amps’ DC protections trigger somewhere around 2 V, and a significant no. of music files carry DC offset high enough to trigger such amps.

Typically, yes.
If no problem occurs there is non.

Professional equipment like the KH120 doesn’t care about DC at all.

Power amps, even those with DC servos, have their own temperature drifting DC offset, service manuals usually state to adjust to <50 mV, but in use, practically the value ends up significantly higher.