Since this wasn't seeing many replies, I went ahead and called support today to discuss my questions. Here's what I could confirm with EyeFi support:
- Hotspot access is "per-card," not "per-account". So, in my example, my 4GB Pro card will need to be renewed once the first year runs out, and my 8GB Pro card will need to be renewed separately after *it* has been active for a year.
- The 1 year of included hotspot access for the Pro cards starts as soon as the card is registered with EyeFi Manager/Center, regardless of when or if you actually enable hotspot access via the software. So, the clock starts as soon as you register your card with your EyeFi software.
- There is no way to verify how much time is left on your existing hotspot access. (That really bites, and I will start a thread in the Feature Request forum to enable some sort of access to this information).
- EyeFi Manager/Center will alert you 30 days before your card's hotspot access expires, and allow you to extend the access via a yearly subscription at that time.
- It is not possible to extend your hotspot access until you enter that 30-day expiration window.
So, as I mentioned above, I'll post a feature request to allow users to check their current hotspot accounts to see how long they have been active and/or when they need to be renewed. I simply think that's a good thing to be able to check and/or know in advance, rather than waiting 30 days before expiration. Users can certainly tracks dates themselves, but it would give us a "warm fuzzy" if we could go to a web page or screen in EyeFi Manager/Center and just confirm what the dates are, and that our hotspot access is currently provisioned to be working, etc.
Edit to add - Here is the feature-request thread