I've got an Aeotec Repeater 7 which I haven't yet added because I'm afraid it will hose everything else. However, I may just try it and see what happens.
The Aeotec Repeater 7 is a good product. Only reason I replaced mine was to get the Ring Extender 2 devices that have built-in battery backup to keep my mesh up during power fail.
I wanted to follow up on your open ticket, but since you created this thread, I will reply here, first. I totally understand your frustration and we know that ghost removal has been a sore subject since C7 launched. We believe that this issue is resolved in the next release. To answer to your last email, we are equally eager to see the next release available to public. While I do not have a time-frame, if testing goes well, it will not be long before the update is available.
With that being said, based on our research, throwing repeaters at your system may not help as much as. Knowing that you have ghosts, I recommend not performing Z-Wave repairs while these are present in your system. I would also screen your logs for any excessive logging from devices, which may be indicative of problems with that particular device. Also, using built-in drivers where possible may help. Lastly, I noticed that a LAN connected device often times out. This alone can make your hub unresponsive at times. If you use integrations like Chromecast, I recommend disabling those temporarily to see if your problem goes away.
I think the nuance was whether or not a non-secure paired device (that supports beaming, obviously) can beam to/for an S0/S2 device. I think it can, but that is nuance I'm not positive of.
LOL ... also @bcopeland keep me honest here but I also recall a nuance with NWI and security devices that NWI wont work if going through a non-secure repeater.
Like @JasonJoel said.. I'm old and I forget things... just vaguely remember some issues with NWI and security and yes that was with 500 series not 700. As you said not all 500 series even supported NWI so it was always hit or miss.
I don't seem to have any ghosts at the moment - at least none that appear as empty nodes in the zwave details. The one I had wasn't able to be removed with the "Remove" button, so I finally bought a UZB stick and used the instructions @danabw wrote to remove it. It worked great after that for several days. I'm really not sure what is happening - if I go into Zwave details, I'll see "Failed" devices which work fine. On the other hand, I have an Aeon minimote in "OK" status but button pushes aren't registering at all. My Aeon nanomote, which worked fine last night and is currently showing "OK" in zwave details is also not working right now. My ceiling fan, which uses a Vision in-wall relay, shows "Not responding" (and many times even Failed) but has never actually not worked.
Likewise for Non Responding. If a device misses a check-in because is sleeping, is marked non-responding. If it continues to sleep, it will be marked as failed. The best way to validate that the device is healthy, is to wake it up. So for a motion sensor means to walk in front of it and confirm that it reports the status change on Device Detail page.
Why did SiLabs do the spec this way? I kinda get the "non-responding" bit but they could have added a first level like "sleeping/temp unavailable". Seems tone deaf at best and misleading at worst... and best of all YOU guys have to deal with the fallout!!!