I’ve been running similar tests and encountered a device-specific limitation that may be relevant to this discussion. On an iPad (A16) (model MD3Y4X/A, released March 2025, iOS 18.4.1), when acting as the Central, the throughput is significantly lower than on other iOS devices. It appears to process only a single packet per connection event, which limits throughput to around 8 kB/s. In contrast, all other iOS devices tested support multiple packets per connection interval and achieve much higher throughput. I’d be interested to know if anyone else has observed similar limitations or unexpected behavior specific to the iPad A16. Hopefully this is something Apple will address in a future update, as the current behavior imposes a significant constraint on applications or BLE accessories that rely on higher throughput that has been supported on iOS devices since around 2017.