TLS orapki, openssl and SAN with EBS 12.2

I was following the note to install TLS 1.2 for EBS 12,2

I have a primary and standby., so I want to use the same certificates across both servers.

That means that I need to have the appropriate Subject Alternate Names.

Due to the vagaries of the certificating system that we use I need the SAN to be in the csr

This doesn't seem possible with orapki from 11.1.1.9.

So the question is do I need to use orapki to create the wallets etc or can I use openssl where I can specify the -ext parameter. Is this a supported method ?

Thanks

Dominic