Those values are not saved in custom license fields and cannot be retrieved from within your app.
The good news is that very soon we're releasing a free license management tool for end-users (your customers) where they can view real-time information about their license (including used / total activations).
And of course, our web API is always available, meaning if you wanted to build your own custom-branded interface for your customers, you can do that too: https://wyday.com/limelm/help/api/limelm.pkey.getDetails/