I was asked to reboot my hub and then wait to let Z-Wave settle down and check the Z-Wave Information page. I did this during lunch today and it sat for at least 5 hours before I checked the info page.
I had 20 devices showing with the following pattern:
Device ID: 2147483647
Device Type: 2147483647
Clusters: in: , out:
They all had the DEAD status and the option to Re-Initialize.
I did this, then after Initializing for a while, I refreshed the page and had the Re-Initialize option again for that device. I clicked Re-Initialize and then was given a FAILED status with a Remove option seconds later. I clicked Remove and the device removed (sometimes it seemed to require me to hold Shift while I clicked Remove then afterwards refresh the Z-Wave info page).
I repeated this process and had 1 that refused to remove.
After removing the rest, I turned Z-Wave off (Settings > Z-Wave Information > Z-Wave Status > Disabled) and then back on.
I waited a short while and then was able to repeat the above process for the remaining stuck devices. I did have a few known sensors not matching the pattern above marked "DEAD" but when I went around and caused action on them (motion=caused motion, contact=caused open/close, etc) they reported as Alive.
Also, removing polling/refresh from Rule Machine as well as just leaving things alone for a day or so it seem to be operating better. I'll know more in a day or two I guess.
Thanks to all that has helped me, including the Hubitat team!