question

First thing I would recommend is you a Cerbo not Color Control GX as it is getting close to end of life and the GX has more software support.

Installation type 1 (AC Coupling):

The meter should be before the inverter. Like Grid -> Meter -> PV inverter. Then the system would use the extra PV power to charge the batteries.

I don't understand what you mean by "For every 1.5 kWp, 4.8 kWh of battery".
You need to size your battery for the power, MIN SOC and runtime you want. BYD LVS has pretty low power output so will need bigger pack. You could use FreedomWon Pack that will deliver 10kw for every 10kwh. So in your setup you could go with a 15kwh pack or 20kwh to be safe. Pylontech you would need around 28kwh. It all depends on the battery you choose.

Grid Meter and Cerbo GX is all that is needed.

Installation type 2 (MPPT Regulator):

If the batteries are fully charged, where will that 9 kWp go?

It will go to loads or be exported depending on settings.

- If the batteries are fully discharged, where will that 9 kWp go?

To charge batteries + any excess from the 20kw inverter.

- If the batteries are at 60-70-80 % of their capacity, where will those 9 kWp go?
Cover loads and rest charges battery

- If the secondary loads consume 10 kW, how will the remaining 10 kW from the inverter be consumed?

- If the secondary loads consume 20 kW and the batteries are discharged, how will the critical loads be fed?
The way ESS works is that it will try keep the grid meter at 0W or whatever you set it to but lets say 0W.
If you have 20kw of solar (Both MPPT and AC coupled combined) the system will work to keep the grid 0W, so
if you have 20kw of solar and 20kw of load then all solar will go to loads,
If you have 10kw of solar and 20kw of loads then 10kw will come from battery,
If you have 20kw of solaar and 10kw of loads then 10kw will charge battery.

If you have 20kw of solaar and 10kw of loads and battery full the extra power will be exported.

Critical and Normal loads are in the same "loads" when grid is present.
When grid is lost then only Critical is provided with power.

- Would it be necessary to put some other equipment apart from the Color Control?
Grid Meter and Cerbo GX is all that is needed. Cables to MPPT

My recommendations is actually a combination of AC and DC coupling.

I would install 15kw of solar AC coupled to the output of inverter and I would then put the other 15kw on a Victron 450/200 MPPT for a total of 30kw of PV.
If you have 48kwh of battery, you could expand the DC PV to like 20 or 25kw. If you want more autonomy on cloudy days.
It is best to have both AC and DC pv so you can do a no grid startup which you can't do if you only have AC PV. It is also better to have all PV attached to Victron Inverter so that in a grid outage all that PV will still work to keep system running and not be just turned off.