I would agree except for this:
"Officially Supported 9.10 Upgrade Paths
The following ZoneDirector builds can be directly upgraded to ZoneDirector build
• 18.104.22.168.212 (9.9 GA)
• 22.214.171.124.212 (9.9 GA refresh)
• 126.96.36.199.216 (9.9 GA refresh)
NOTE: If you do not have a valid Support Entitlement, you will be unable to upgrade
ZoneDirector to this release. See Administer > Support page for information on
Support Entitlement activation.
Due to the enforcement of the Support Entitlement feature in ZoneDirector 9.10,
Ruckus recommends upgrading to 9.10 from one of the above 9.9 builds only.
You can also upgrade directly to 9.10 from one of the following 9.8 builds. However,
you will be prompted to reset to factory defaults before the upgrade can continue.
(This is not required when upgrading from 9.9 to 9.10.)
9.8 builds that can be directly upgraded to 9.10 (requires factory default):
• 188.8.131.52.379 (9.8 GA)
• 184.108.40.206.101 (9.8 Maintenance Release 1)
• 220.127.116.11.15 (9.8 Maintenance Release 2)
If you are running an earlier version, you must first upgrade to one of the above
builds before upgrading to this release."
You basically have to go to 9.9 before 9.10 unless you want to reset config. This doesn't mention if you can do a restore, which I hope you can?