Been working on my first unit, and discovered it has i/o instability, but I am unable to trigger the problem on demand which is really frustrating, likely either RAM or storage, both of which I took as inclusive (my previous NUC's I ordered barebones and used known brands for storage and RAM).
The unit has a internal mPCIE which is pin compatible with mSATA however installing a mSATA drive confirms its not connected to the onboard SATA controller. It has a normal SATA port for standard SATA drives and 2 NVME, one for 2230 and another for 2280.
I got no LPDDR5 or NVME lying around, memory tests come up with nothing, extended SMART tests clean on the storage and has clean SMART stats, file system checks however fix corruption on the drive. The BIOS is the most thread bare BIOS I have ever seen in a NUC, its like a laptop BIOS.
So will chance it and buy a 2230 NVME, as that will work in either NVME slot, so if the NVME slot is duff, it can get round that, or if its the existing NVME it will solve the issue.
Luckily the other NUC I brought bare (after realising the included components were only saving £30).
Also the speaker is soldered directly on to board with no jumper to disable it, there is jumpers to control always on behaviour, pin 1 isnt labelled, so those I will tinker with later as I am curious if will fix the shutdown/sleep issues.