Hi DaveF, currently that's not an option on the Desktop version, but it will come on a future update. Just FYI, in case you try to connect your ElectrumX server to the mobile apps, self-signed certificates aren't accepted, but you can use a certificate from any free CA like Let's Encrypt for example.
Even though CA like Let's Encrypt is free, AFAIK you still need public static IP or domain in order to get the CA, which is quite costly.
Not really there are a lot of DYDNS services out there so static IP is not a real concern. My lightning node is behind a dynamic IP and is updated in more or less real time.