vSphere 5.5U2 to 6.0U1 Migration- 3 vCenters and 2 SSO logical Domains -> 1 Unified SSO Domain

Hey all,

I've been through most of the official vsphere 6 docs and KBs, plus some blogs here and there. and I still did not find a definite answer to what I'm trying to achieve.

Basically, I have the following setup [2 vCenters in linked mode, with Embedded SSO | 1 vCenter with Standalone Embedded SSO]:

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I'm trying to do vSphere 6 upgrade and get benefit of Enhanced Linked Mode. and to future proof my setup. thus, I want to have PSC on separate VMs.

KB2130433 Addresses the below part of the setup:

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But I'm not sure about the other part where I want to join The third vCenter to the new PSC unified Domain.

I have the following plan in my mind (derived from KB2130433):

1. create 3 new VMs
2. install a new SSO in VM1 ( with First vCenter / Standalone Option )
3. install the 2 other SSOs in VM(2/3) ( with Multisite / New logical site Option )
4. Re-point First vCenter ( with Main SSO )
5. Re-point Rest vCenters (including Standalone vCenter)
6. Uninstall Embedded SSOs in all vCenters
7. Do Upgrade from SSO 5.5 to PSC 6.0U1
8. Upgrade vCenter 5.5U2 to 6.0U1 Directly

Does anyone know if this would work or not? Suggestions for other approaches?

Note: if a reinstall is required of any of the vCenters, I really must keep my inventory details (VMs Tags at least).