Exactly, I think that's how the setup looks - only that the Z2 here is also a two-way meter.
So far I haven't had to pay anything - are these meters always rental devices? I'm not particularly keen on having to pay rent for meters that I don't necessarily want/need :D
These are almost always rental devices. You can ask the [VNB] if it would also work with two meters. Unless you have some kind of developer/residential area construction where you have no influence.
The metering point operator may charge up to €20/year per modern measuring device. The "up to" means he does not have to charge a fee, so if he doesn't, leave everything as is. ;-)