It's a flop for the backlight LED going out below 2.6V and the fake 100 segment bargraph.
From the videos, it's in groups of three, so around 30 segments. Dave got fooled
Not really worth adding that big IC to drive a few more LCD segments?
I don't mind the negative contrast/transmissive LCD.
The DMM IC has a charge-pump for the LCD drive, add a few parts and it should be able to drive the LED's, although noise will affect the uV range.
Looking at AA battery discharge curves to 1.35V it looks like about 1/3 capacity and usable for about 60hrs at 16mA drain
Energizer E91Duracell professional leakers.
Latching relays are notorious for changing states when bumped.
Not sure what this meter does if it plops over due to the crappy stand. I hope it stays safe if the relay changes by accident.