Revised analog front-end : Replacing the analog switch, part 4/4

In the post for the automatic voltage range, I used the analog switch ADG5419 to switch between the low and the high voltage ranges. I was wondering if the switch can be replaced with the shutdown feature of the LTC2057 op-amp. According the datasheet when the LTC2057 is in the shutdown mode : "... the output presents a high impedance to external circuitry". If the outputs of the op-amps are shorted and the SD inputs are feed with opposite signals for each op-amp, in theory this is equivalent to a SPDT switch. The switch is not expensive one (it cost around 5USD), but the maximum voltage which can stand (+/- 22V) was less than the voltage which I will use for the LTC2057HV. So usage of the ADG5419 cost me 2 more power rails which I want to avoid.

Тhis raised the following question : what kind of glue logic ("A" in the schematics above) I have to put between the outputs of the MAX990  comparators and the SD/SDCOM op-amp inputs? 

The output pin of the MAX990 is an open drain and a pull-up resistor to the positive rail have to be added. The voltage outputs of the MAX990 are between -2.5V+Vds(of the open-drain stage) when input voltage is above 2.048V and +2.5V when input voltage is below 2.048V.

From the LTC2057 datasheet we have the following information: "Shutdown control is accomplished through differential signaling. This method allows for low voltage digital control logic to operate independently of the amplifier’s high voltage supply rails.". And the tables with the logic and operating voltage ranges:

From the operating voltage range we had the restriction that voltage between the SD and SDCOM must be no more than 5.4V and it should be between the op-amp's power rails (except for the SDCOM max value). This was fine as far as the MAX990 outputs are between -2.5V and +2.5V. If the SDCOM is connected to the -2.5V power rail, I need two opposite signals from the MAX990 outputs which to be connected to the SD pins. 

I thought : why not to put an NOR gate 74x logic? The negative input voltage is not a problem if the Vss is connected to the -2.5V power rail and the Vcc is connected to the +2.5V. So, I made a breadboard proof of concept and putting the scope probe on the shorted outputs of the LTC2057 op-amps, I got a very clean, 2 us transition time between the two input signals.