Hey Jason, good to hear from you. For the older models the max was 100 per radio, you are correct; but for the newer models, and the AP650 specifically, the max client count is 250 per radio. That count is in a lab environment though, production environments typically won't want to go all the way to the max client count if the clients are passing anything beyond a minimal amount of traffic.
For the Client Related Network Settings, specifically the maximum client limit, that is going to be per SSID. This is an excerpt from
the help file for that XIQ page:
Maximum client limit: Set the maximum number of clients that can associate with an SSID on an device. The default is 100 clients, which is the maximum number of clients that a single radio supports. You can change this to another maximum between 1 and 255. For example, if you want one SSID to be able to serve a certain number of clients—say 40—you can limit all the other SSIDs on that radio so that the sum of their maximum client settings does not exceed 60. Doing this ensures that the first SSID is able to serve 40 clients before the 100-client per radio maximum is reached.
To set the maximum number of clients you want on the AP radio in general, you'd want to go to the Radio Profile and set the Maximum Number of Clients to what you'd like it to be:
Is that what you were looking for? Please let me know if I can clarify anything!