ummm.. No.
ZWave is backwards compatible.
There are individual manufacturers that have managed to mess it up, but for the most part, Series 500 and 700 modules are able to route/pass along any packet
If you have a lot of series 100 and 300 modules in your devices, there's a slightly larger opportunity to have a path problem but it's a little ways out there from a practical standpoint.
That's great news, I'm glad I don't have to maintain the mesh at a particular level.
I'm still concerned that 2 different manufacturers claim to have S2 support on their devices, and I have been unable to get my C7 to recognize either of them.
I have both, connected to a C-7. The Inovelli Red dimmer found a 'better' spot in my home and because I'm using 3 Hubs, one for physical areas of my house, that dimmer is now on a C-4 where it's unsecured. I can't SHOW you I have a success with that anymore. But I can show the Repeater 7:
OH.. I have an unopened Red Dimmer sitting here that I bought during their sale a week or so ago... do you believe me or should I open this one up and Include it as proof?
None what so ever...
I agree.. repeaters are a no, BUT it was a new C-7 and I wanted to see it work. 
So, maybe one reason LOL
In other words, New C-7, New Aeon Repeater 7.. MUST PLAY I don't remember doing anything really. Certainly nothing special.. other than finding the code on the paper that fell to the floor.
I don't know why I even have it.. the ONLY thing that is using it is a battery device that seems always to be 'away'.
OH.. I have an unopened Red Dimmer sitting here that I bought during their sale a week or so ago... do you believe me or should I open this one up and Include it as proof?
Dude, I'm not arguing what you are or are not able to do. You've got multiple generations of hubs, I have whatever the most recent thing Hubitat sold me at whatever the most recent level of software support is. I've got the same dimmers in the same retail boxes man - I've got multiple switches with different levels of firmware for troubleshooting. I just want my stuff to work.
What steps did you do to pair successfully? I'm happy to replicate them right now, because again, I just want this to work.
Same here.. which is why I'm asking...
My thinking is, someone saying "it works for me" can ADD to frustration, not help. BUT I'm saying if it would help. I'll help. 
Here's what Mike Maxwell provided on this
I am intermittently getting this prompt when attempting to add devices. Regardless of the options clicked, my devices end up in the zwave settings menu with Security: None.
Am I adding it wrong, or do I need to do something else after the fact?
In the screenshot below, the Ring Range Extender 2 (device 0x08) is paired securely only because that's the only way it will report power fail. It's in a GFI socket in our garage that trips sometimes when it rains, and our freezer is plugged into the GFI socket, so we are alerted when the GFI trips. Devices 0x09 and 0x0A are Aeotec Range Extender 7 devices, and are next to the Front Door and Back Door (devices 0x07 and 0x06) Schlage BE469ZP locks to make them reliable.
The only way I was able to get any S2 devices to pair was to have the HE within a foot of the devices. Our Zooz ZEN16 (controlling patio fireplace LED controller) was so slow (several seconds per operation) when paired securely that I took out the secure pairing, otherwise the LED controller, which requires that it be turned on, then off, then on, quickly within a second or two in order to place it in a cycling color mode, couldn't be controlled.
Other than needing the Ring Range Extender 2 to be paired securely in order to report power fail, the only secure pairing I care about is the lock pairing.
Just wanted to mention that I love using the extender as an outlet monitor as well. That's smart!
While in general I agree that there is little to no value for having a repeater securely included, I do know of a couple exceptions:
Ring Alarm Range Extender (Gen 2) - This unit ceases to function if not enrolled securely.
Aeotec Range Extender 7 - This unit appears to prohibit firmware updates if not enrolled securely.
You can work around the AE7 issue by excluding and re-including, but that can be a bit of a problem if you have routes through it.
Not true. The Ring Range Extender 2 won't report power fail status unless it is paired securely. Confirmed by testing of my Ring Range Extender 2. See above screenshot.
Another way to say it...
There are no specific protocol benefits from having a repeater device paired securely. There may be instances where there are device specific benefits to having things paired securely, though.
My personal security rules have become:
Ok, sure, I blame this on the device (not reporting properly with security disabled), that just makes no sense...
Most repeaters don't report anything, this one is the exception, not the rule...
Mike:
Do you tend to just unselect all the S2/S0 security options when the S2 dialog comes up on the C7 and you're not pairing a lock or some other device that you don't think benefits from security?
Yes, personally I only enable security on locks and other door controllers, that's me, to each his own.
Yes, personally I only enable security on locks and other door controllers,
That sounds like best practice and I'm going to try it myself.
Thanks for clearing up some confusions around the S2 pairing, just because it can doesn't mean it should
Same goes for S0 in my opinion, but S2 is much more efficient than S0 so S2 is less imposing on the hub and the mesh...
Download the Hubitat app
