dcV:
40mV OK
400mV meter: 198.1mV software: 1,981V
400mV meter: 198.1mV software: 1,981V
4V OK
40V OK
400V meter: 046,8V software: 468V
1000V OK
jar file V0.83 where the extra factor is 0.1
I was missing the hex dump to confirm it was the extra decimal location.
dcV is 100% now

I start checking other functions.
I've also discovered I can use ctrl-c to copy data from the command screen (right click copy doesn't work) so that makes it easier for me to include the hex dump when something isn't right.

edit:
dcA is 100%
resistance is 100%
Temperature in C is correct, in F converts to C in software, maybe intentional.
Frequency including duty cycle is 100% up to 99,99Khz range, above untested.
acV is 100%
diode and continuity is 100%
capacitance is 100%
A minor imperfection is that on all ranges that I've noticed OL is displayed as 0, for instance MOhm range:
;; COM6: Rx: 0.0 2B 3F 30 3A 3F 20 32 21 00 10 20 29 0D 0A