Only have one meter, config wants meter 2 to be populated, creates error 823 in log

[Kommunisator]

Hi,
I only have a single reader (Easymeter) that outputs on 2 channels. I had this working on an external vzlogger (using a pi), however I wanted to integrate everything into the HA VM.
The IR reader connected via USB works, settings are d0 as protocol, 7E1 for parity and 9600 baud. Using this, I can get a useful output in the console.
The reader is set up by-id, insted of using the port, since I have multiple USB devices tunneled to this Proxmox machine.

I have set it up in such a way that the readings of identifier 1-0:1.8.0 and 1-0:2.8.0 are set to meter1 and 1-0:1.7.0 is set to meter2 since I had to specify a second meter - the addon wouldn't let me run it with the meter 2 commented out in the config file, and produced loads of errors or wouldn't run if the fields of Meter2 were left blank (even though... there is no meter 2).

The result in the log is:
[d0] Something unexpected happened: read:823! in logfile

Finally, I get no MQTT connection error, and two other devices work fine with Mosquitto, but even if I try to manually listen to vzlogger/data, I get nothing there. Mosquitto also didn't detect a new device all by itself, like it did with my vacuum robots.
I tried using localhost (didn't work), 127.0.0.1 (didn't work), hostname without domain addon (didn't work, although it is pingable), using the FQDN with the local domain suffix fron the router (works), and the LAN ip (works). With "works" I mean that I did not get any connection errors in the logfile. Using localhost results in connection/authentication errors (Mosquitto might not like internal connections?), using the hostname without domain suffix or any wrong entry results in an instant no-connect without any further retries (according to the logfile)

At the moment I am quite stumped on where to look next. I also couldn't find any documentation on this error code (seems like a VZlogger error, had no luck in other communities too).
Can you point me in the right direction on how to
a) use this addon with only one meter and
b) force it to connect to MQTT on my local machine?

[Kommunisator]

As an addition:
Uncommenting the whole meter2 part does not work, config cannot be saved after that.
Removing the device lets you save the config, but then you get this error in the log when trying to start the addon:
[Oct 24 01:07:56][d0] Missing device or host
[Oct 24 01:07:56][] parse configuration failed due to:
[Oct 24 01:07:56] Failed to parse configuration due to: device without length
After that, all services are stopped.

you also have to have at least one identifier and aggmode in meter 2, even if no meter is specified, otherwise the config will not be saved.

[Kommunisator]

Just found out by accident (deleted some other parts) that the Error 823 can be removed by setting the parity of the second Meter to 8N1. Even though in my current config, Meter 2 is reading stuff that Meter 1 also has configured (1-0:1.8.0).
No response from Mosquitto though.