Hi there,
We switched to the internal SD Card slot. No more latency spikes and seems to do the job - the dual MicroSD seemed to be a good idea (and it probably is) but the dependency on the USB slot seemed to remove the advantage you were meant to be gaining.
I haven’t searched extensively but a server will external facing SD card slots that are mirrored seems to be a great idea but not something HPE does.
Kind regards.