High and Unstable Network latency on wired connection from SXS50 to main router SXR50

This system appears to bundle a 5-year subscription to Insight support.  It would be interesting to hear what Netgear support says about this issue. From the Product Data Sheetpage 3:

The SXR50 system uses a 5G WiFi channel to connect the router to both satellites, which means that when any of the three is transmitting, the other two must "wait their turn".  Because there are only two 80Mbps WiFi channels available in the US (and also in Europe), any nearby tri-band WiFi systems may also be using the same channels, which would result in more contention for available radio time.

In a normal residential environment (not an apartment building with 20 nearby WiFi systems (above, below, and next door), those results do not seem reasonable.  I tested my original RBR50 system and found average pings across the WiFi backhaul link to average 3-4ms.  An average of 143 seems unreasonable.  It is not unusual for the very first ping to have a long response time, but 1775 averaged over 1,000 would add at most 1.75ms to the average.

Should probably ask, "Is this a matter of intellectual curiosity?"  (I love to go "down the rabbit hole".)  Or, is there an actual performance problem that if affecting use of the system?