Downgrading license from 14 to 12

[valerio_vanni]

I am one of the old cpu owners that cannot use 14.

So I have to buy 14 and use 12 (now I have 10, and I need to upgrade it).

I've searched but I was not able to understand how downgrading licenses works.

Here I find an howto about technical downgrade:

Downgrading from VMware Workstation Pro 14 to VMware Workstation 12 (2128613) | VMware KB 

And here another one about license, but it's not about Workstation.

How to downgrade license keys in My VMware (2006975) | VMware KB

How do I downgrade? Can I buy 14 and use directly its license key on 12?

[valerio_vanni]

I found in my.vmware.com the option for downgrading the licenses. It appears in my Workstation 10 license number, and I hope it will appear also in my future Workstation 14 number.

Another thing I don't know: after having downgraded a license number, when I'll have a CPU supporting 14, will I be able to upgrade the license number back?