Earlier quoted context omitted.
I'm struggling to think of a browser that supports SHA-2 TLS encryption, and doesn't support SNI, which one am I missing?
Windows XP and Android 2.x comes to mind. Non-HTTP protocols (IMAP, SMTP, XMPP, SIP etc) may also struggle with SNI. But the biggest problem here is wildcarded subdomains, since LE doesn't let you get more than 5 certificates per domain.
Also I think with Firefox on Windows XP it should work.