Daikin RZP100, solenoid valve Y2S( SVC)

Hi to all the experts!

I am writing here because Daikin could not answer in a simple way to the question posed.
The problem is a Y2S solenoid valve (SVC).
Well, under what conditions is this valve opened?
The RZP100 manual describes it as follows:

"Subcooling heat exchanger control
Conducts ON/OFF control of the solenoid valve for subcooling circuit as follows.

• When the compressor operation frequency is at step 10 or lower or either temperature of discharge pipe or suction pipe is low, the valve does not open.

• Collect the oil by opening the SVC for 10 seconds in oil return mode."

Under what conditions, in the heating mode of the RZP100 the Y2S solenoid valve (SVC) is activated to increase the capacity by cooling the liquid refrigerant passing through the double tube heat exchanger (pipe within a pipe), the manual entry is quite enigmatic.
Maybe some fellow forum members are able to help?
Best regards, Waldemar

Does no one really know the answer?

Don't you believe the Daikin manual?