Kostal Plenticore Plus 10: external battery management

I’m using the Modbus interface for my Kostal Plenticore Plus 10 (BYD 10kWh).

So, using external battery management you have to send the commands as long the timeout (60s configured) is not met (similar to expire in OH).
What I did last night was:

  1. tell the inverter to charge my battery from the grid
  2. tell the inverter (later) to have a maximum discharge

First command was running for some time up until 6:00 sharp. openHAB then stopped sending send any commands regarding chargePower (or modbus #1034). But starting with 6:00 sharp, openHAB started sending dischargeLimit (or modbus #1040). The change was simultaneous, meaning there was a constant “external batterylimit”-flow. But what I discovered was, that while the dischargeLimit was sent, the inverter still followed the “old” chargePower command, which wasn’t sent anymore.
I paused the rule for a minute and started it again, and after the external Batterymanagement was completely abandonend, the inverter then did what was expected: only followed the maximus discharge limit.

So, my question is:
is there some kind of “delete”-command for a specific modbus register neccessary? My impression was, that if I don’t send commands within the time-out interval, that specific command would be discarded from the inverter anyways - even though another register within the external batterymanagement receives commands?