How to best measure parallel wired old Battery/charger inverter

Hello fellow Victron enthusiasts.

I have installed an ESS system and it is working as expected. My setup is as follows:

1.- ET112 at grid ingress to home to monitor energy flow to/from Grid

2.- Cervo GX

3.- two PV solaredge inverters in parallel to Multiplus ii L input

4.- a bank of 6 Pylontech 2000c batteries.

All working fine.

2 questions:

1.- I have an old inverter/charger for batteries that is also wired in parallel to L input. I would like to “see” this unit on Cerbo and been able to make policy decisions. What is the best way to see this inverter. I could think of the following:

A.- install another et112 to see current flow from/to inverter

B.- use a CT and hook it to current sense Ext port of multiplus (would this work?)

C.- use a victron shunt to see batteries connected to the old inverter

Which one would be best?

2.- I am also using the schedule charge function of the ESS assistant to charge batteries at off peak cost times (middle of night) to have “some” battery storage early in morning when peak costs start. I would like to dynamically adjust the amount of charging I do at night from grid dependent on the weather forecast of next day. If cloudy forecast, maybe increase SOC at night to 60-80%. If sunny forecast next day, only charge to 40% to cover morning loads until PV is sufficient to cover home loads and start charging battery.

I can think maybe using nodeRed although I never used but wanted to ask if anyone has done this setup

Thanks in advance and sorry for the newbie questions. I am making my way to learn more to maximize my current setup.