I will try again with the nRF52840 Mbed version release 2.9.2.
I faced issues with the latest non-Mbed version 1.1.3. The recommended solution as per XIAO BLE wont compile ArduinoBLE- Arduino IDE - #11 by msfujino is to use the previous 1.1.1.
I fully agree with you. The Xiao boards are incredible pieces of hardware: let’s hope software and collaterals be on par!