Not sure I’m following. Iris gen 1 devices are forming their own mesh network, as are the other zigbee devices (using the ZHA 1.2 profile) paired to the hub, as are any z-wave devices.
One hub is capable of handling all these devices, but then one has to have enough repeaters to form a stable mesh for all three wireless protocols, spend time building out three meshes, etc.
OK.
is another hub
Sorry I still don’t understand what you mean.
IF you have a set of Iris v1, they create a mesh.
IF you then add ZHA 1.2 devices to that SAME mesh, the foibles of Iris v1 can impact the ZHA 1.2 devices because they share one mesh, one set of repeaters and any ONE repeater that isn't 100% perfect in repeating both CAN impact the other. Maybe it's that a v1 device only has buffer for 16 packets, assuming they are v1 sized packets BUT pretend 3 ZHA 1.2 Power Sockets can overwhelm the buffer intermittently. Perhaps it's larger packets, perhaps more reports per second. Power, voltage, amps, energy. There is nothing quite as frustrating as intermittent.
If it works, great, but if not, have this idea in the back of your mind, that's all. 
My read of the advice is: if you have two well built Zigbee meshes, they can't possibly interfere.
I have 4 'well built' ZWave meshes, so I know it's not inexpensive advice.
Thank you csteele for expressing so well what I could only mumble about!
I'm sure I don't fully understand the difference between devices that use the ZHA 1.2 profile and iris gen 1 devices that use... whatever they use.
But if I'm understanding you correctly, Iris gen 1 devices and any ZHA 1.2 devices paired to the same hub will create a single zigbee mesh? I suppose I assumed that since they can't be paired to, say, a smartthings hub or an echo plus, the magic that @mike.maxwell worked to get them to work with hubitat meant they were put in their own corner, separate from the zigbee devices that play nicely with others.
@mike.maxwell said, if I'm remembering his early messages about the possibility of solving the Iris v1 conundrum, that the Packet at the high level was a standard Zigbee packet, and that it was the interpretation of the data within that made it a puzzle.
In other words, before he started the journey, v1 devices would BEGIN to pair up.. then stall. That convinced him that the Zigbee radio could 'see and understand' the packet... but the platform wasn't understanding the data within. He solved that, obviously.. but he has no control over the way an Iris v1 plug works. If it defines itself as a repeater, it is. And it repeats all the packets it sees... but that does not mean it does a good job of it. 
Maybe it's slow.. slow tiny processor, maybe it's buffer limited.. tiny processor and memory.
That's my interpretation... Maybe we'll find out which ring of the dart board I hit.. assuming I even hit the correct wall.
ZHA is an application layer protocol that runs on top of the zigbee transport protocol.
Both ZHA 1.2 and Iris V1 (alertMe) use the same transport layer protocol, but different application protocols.
Think of it like your postman being the transport layer, and the contents of the letter being the app layer, the contents of the letter can be in any language so long as the address can be read.
Anyway, the v1 devices have a slightly different inclusion process that isn't compatable with ZHA devices and the device commands are completly different than Zigbee certified device commands.
So both v1 and other zigbee devices can exist on the same hub.
Due to their age, lack of firmware support, lack of new development and a depricated zigbee profile, we don't recomend purchasing these devices for new installations, despite their apparent bargain value.
I received my repeater and set it up. Paired in place like the instructions said, but my rules were still struggling, so I ended up relocating it to the other wall closer to my schlage lock, on the other side of the wall in the garage, but still central to my Alfred lock on the other side of the other wall to the garage. I repaired it and gave the hub a reboot. I will have to say that the locks started responding better. Since last evening, I've only had one drop (actuallly, I think the hub locked up or the lock got stuck) but I had to reboot the lock to fix it. Since adding it, my rules have fired every time and both locks are responding. And announcements have resumed. I can't explain this. I don't want to understand it. I'm just happy that my mesh responded this well.
Then buy 3 more 
can never have too many repeaters. Most (not all yet) outlets in my house are z-wave plus.
I probably will, but my problem is that the house has switched outlets. It would be quite an undertaking to change that. Circa 1994 crazy man wiring. Boy do I have some stories.
Ugh... yeah the two bedrooms in the main section of my house had switched outlets. Not anymore thank you 
I don't mind them in the living room, I have a smart switch running them, for lamps/. But that's where the repeater worked best.
Had to re-install both my locks after separating my Sylvania bulbs to the Upstairs hub and now I can't get the front lock to communicate. I think I'll be looking into the Aeotec repeter or a generic Zwave plug repeater.
Kudos to @aaiyar for the great suggestion on moving the Sylvania bulbs to a separate hub. Everything is working great now. Not perfect, but it'll improve with time.
I was let on to a pack of 2 aeotec 6's for $54 on amazon. That's the best price. I paid $29 for one. Learn from my mistake and search it out.
I was going to buy a GE Zwave light switch to fix my Z-wave range issues, but felt the signal boost wouldn't be enough. I went the same route as you except I opted for the Aeotec 7 because of its 250% range improvement over v6. Since I only have the 2 Z-wave devices, which are my locks, this seemed like a better solution than a switch.
If I had more Z-wave devices I'd probably be all over that 2 pack from Amazon.
See .. I have a good number of zwave and zwave plus in my house. The footprint is only 30x60, so I don't really understand why it was necessary. I'm sure someone with a marker and an easel could explain it to me. I'm glad you opted for the upgraded one because it has the new zwave module in it. You'll have to report back on how it's working. Although there isn't much out there yet with the new module to really test.
Download the Hubitat app
