Do you have a source from the Z wave alliance for that? Because respectfully, that’s not how it works. Each individual device is limited by its own range, but it’s not affecting range of any other device. And as long as the controller is Z wave plus, any path along zwave plus devices to it will be able to take full advantage of zwave plus features, even if there are other Z wave classic devices on the network.
The zwave standard has always required being backwards compatible, but that doesn’t mean that the newer generation devices get slowed down to the speed and range of the older ones.
Imagine a network with the hub, a zwave plus switch in the entry way, a zwave classic switch in the kitchen, a zwave plus motion sensor in the basement, and the hub one floor up in the hallway with a zwave classic sensor there as well.
The classic kitchen switch is too far away to reach the hub or the classic sensor upstairs. But it can reach the entry way switch and it can reach the basement sensor.
The entryway switch can reach the hub upstairs, but it can’t reach the basement sensor.
Now imagine you have a delivery service where some parts of the routes are handled by van (zwave plus) and some are handled by bicycle (zwave Classic).
We want to get a message from the basement sensor to the hub.
So it starts out with a van, which covers the distance to the kitchen switch. At that point the message is given to a bicycle rider, who delivers it to the entry way switch. That’s zwave plus, so we go back to a van, which delivers it to the hub.
Only the part of the route which was transmitted by a zwave classic device is limited to Z wave classic range and speed. It doesn’t in any way change how fast or how far a different switch can transmit.
Now imagine we are sending a message back from the hub to the basement sensor.
Again, it goes by van to the entryway, but then it also goes by van to the kitchen switch, because it is the Z wave plus switch which is transmitting. So a message travels faster in one direction than the other, because the limit (which again, only applies to that 1 hop) is based on the device doing the transmitting, not the device which received it.
OK now let’s look at a different route.
Suppose there is another Z wave plus switch in the dining room, and it can reach the entryway switch. It can’t reach the hub directly.
When the dining room sends a message to the hub, it goes by van to the entryway and then by van to the hub. Full zwave plus speed all the way. It is not in any way slowed down just because there happens to be a zwave classic switch in the kitchen.
So mix and match all you like. That’s one of the design intentions of Z wave, that people do not have to replace older generation devices unless they specifically need the features that come with a newer generation.
The older devices will only slow down the specific hopfor an individual message, and only if they are the transmitter of the message for that hop. Which is a good thing when you’ve invested a lot of money in devices which worked just fine the way they are set up.