[Elecraft] Want confirmation on 8R line understanding

[Robert I. Block W2SR]

I want to mute my K2 while using another transmitter by pulling the 8R line to ground.  Before I do anything drastic, I'd appreciate
any comments to ensure I understand what's going on.

It appears, based on the documentation and schematic, that 8R is asserted by RX from the MCU (in accordance with the TR and 8R hold
settings).

While asserted, 8R provides 8v at up to 2 ma to an accessory or keying device attached  through the KIO2 or Xverter interface (such
as the Amp Kit).

While de-asserted, 8R will sink 2ma from an external keying device.

Here is the part I'd like verified:

True or False?
Even when RX is asserted, 8R can be pulled to ground by a low-impedence sink (such as Q23 on the RF board, which guarantees that 8R
is low when 8T is active).  Therefore a copy of the Q23 circuit attached through the KIO2 can be used to mute the K2 in response to
an external mute signal.