thought I’d link to this re significance of number of names per SAN, though I haven’t modeled this myself (yet)…
https://serverfault.com/questions/453475/how-do-san-certs-degrade-performance

my take away from that and other sources: there should be really no significant difference for most use cases between a cert with 10 names and a cert with 50 names –> meaning, just stay under the 100 name limit because the ‘limit’ has been essentially standardized at 100 to limit potential for performance issues… and that was back in the day even, we got generally more bandwidth now –> so, stay under the limit especially if you have long names (as addressed above), and all will be fine 🙂