Just wanted to tell about my upgrade and things i learnd when i was upgrading, i was switching from HA running on raspbian to raspbian buster and hassio in docker. Learnd the hard way that docker is much better when it comes to upgrading. Wanted to use hassos but it dosnt support booting from USB. Anyway read allot about how easy it suposed to be migrating my devices. Ended up using the whole day figuring this out and was allmost going to reset and start adding all my devices back in maually.
what ended up working for me was:
/boot/config.txt added:
enable_uart=1
dtoverlay=pi3-disable-bt
z-wave worked on ttyS0 but was buggy. errors like: Notification: ControllerCommand - Error - Failed, and WARNING: Out of frame flow! (0x30). Sending NAK.
stoped the docker service, installed z-wave.me service and disabled it, started docker again and ha said that ttyS0 wasnt available, changed to ttyAMA0 and it was working again, and yeah another thing it wasnt enough just to copy over .storage settings i had to copy over zwcfg file. and remember stop your z-wave service in ha before you copy it over because if you copy it over and reboot ha saves current settings and overvrites what you just copied.
hope this helps somone else running into same problem, and saves them a few hours 
br
Roffer