Hi PJ,
MG24, which is very similar to nRF52840, is being evaluated, but so far it is not very attractive.
The DeepSleep current is indeed less than 2uA, but it easily reaches 5uA when the room temperature rises, which is the same level as the nRF52840.
In my opinion, the 8-port pads on the back side is not necessary so many, rather the ports should be used for IMU interrupts and boot switch.
I will post a report after I finish my evaluation.