Thanks to HighPrecision, I've been able to get a copy of an old version of the EIP documentation "Additional Service Information for 5XX CW Counters". It's unfortunately unavailable online, still, it contains a lot of valuable information.
The part dedicated to verifying the Band 3 Microwave Converter (A203 ...
This part is about my attempt to modify the firmware to "fix" the problem of weird intial setup: a -160MHz offset and a resolution set to 5 digits.
In the previous part, we figured some probable spots in the firware where these default setup configurations might be set.