LQI numbers are a pure matematical value generated by the stick. It is not showing any actual link quality, just a representation of the signalstrength time something, hence the number is not comparable between coordinators. I have a similar story as jerrm. Early I was running a small conbeeII network with a few sensors and no mains. All devices was having 255 in LQI, however frequently missed actions like door open etc. After including a number of mains I got lower LQI, however solid and stable mesh (except for the know problem with conbee when changing a lot of devices at once, some misses). So, LQI numbers do not really tell anything, at least that is my conclusion.
Lately I have created a new zigbee mesh using a Sonoff 3.0 dongle and Zigbee2Mqtt. Like jerrm I created it for the fun and test, however I like the Zigbee2Mqtt implementation better. Yesterday I move the last few devices, so my ZHA network is empty.
My Sonoff network shows LQI in the range from 10-130, however being rock solid and faster than ZHA based on conbeeII (LQI, in range from 150-255).