Surely ability is determined by having the proper inverter though? The panels are irrelevant as without a proper grid matching inverter all connecting to the grid is going to do is destroy the inverter.
Also, as someone who is currently going through the process of registering a grid connected inverter here in the states, surely the whole point of the registration process is the part where an appropriately licensed electrician comes out to physically verify that the inverter is grid compliant and anti islanding, as that is the part that is likely to actually kill someone if it is improperly installed or configured.
It’s also something the government/utility has to take on trust to be declared, as a miss wired generator or battery backup transfer switch poses the near exact same risk.
Unless you’re meters have a whole lot more protections built into them than ours I don’t think that they would have anti-islanding or grid frequency protections built in, that latter at least seems like it has to be done at the inverter level.
If it is the case than why bother with any registration or monitoring at all beyond requing a smart meter for anyone with a grid tied inverter?
As for the meter reading itself it’s going to depend on whether the inverter is connected to the gird, and if it is whether or not the inverter is set to grid export or only to provide as much power as the home is using at the time, possibly minus something for reactive power or some such.