Useful compilation RDB, thanks for that.
It's also possible to use one cert with one IP and multiple Vhosts by using the server name as the CN, and subjectAltname defines in the certificate signing request, where each define is for one of the vhost sites.
CN - ourserver.usefulhosting.com
subjectAltname1 - www.domain1.com
subjectAltname2 - www.domain2.com
Not very practical if one is adding and removing sites on a daily basis, but it does work