Control-S dead time on Sat-A2 DSS

I've been playing around with controlling my Sat-A2 via Control-S. I'm seeing behavior similar to what has been discussed in the archives, but have a few more observations to kick in.

As noted, when the receiver is set to use the RF remote, the Control-S input is ignored, and the only Control-S output is that the line goes high for two seconds when certain keys are pressed.

What I've discovered is that when the receiver is set to use the IR remote, the Control-S output is still raised for two seconds when those same keys are pressed. Further, while the output line is raised, the input line is competely ignored, but the IR input is still honored.

This line-raising happens after each keypress when attempting to enter a channel number, athough it doesn't happen when using the keypad to negotiate the menus (but pressing the menu key does). The line appears to be raised the instant the command code is recognized; if I send the menu code with five repeats while reading the output from the DSS, I consistently see two repeats of the code, and about 4ms after the last bit the line goes high.