I just hounded HDPlex again.
This is what came back:
"I have developed a NUC kit for the next batch of H1 V3.
Here are some pictures.
The NUC kit is installed inside my H1 V3 case.
NUC kit supports the same six heatpipe heatsink system which is designed for Intel 65W TDP CPU. Therefore there should be a wide thermal margin for NUC which usually does not exceed 35W TDP.
Please note, the NUC board is installed upside down with CPU side facing top. The copper base in the NUC kit supports three point installation pattern for NUC 7th, it i also supports four point installation pattern first appear on the NUC 8th gen.
A NUC I/O shield is installed on the H1 Thin ITX backplate. Every new generation of NUC might require a new NUC I/O shield.
The NUC kit will include two I/O shield. See attached picture. One for I/O with TB3 and one HDMI, the other for two HDMI type.
There are also two USB 2.0 port on the I/O shield since NUC has two onboard USB 2.0 port. There are also two USB 3.0 side port on the H1 side plate. Those two USB 3.0 side port will be connected to NUC front USB 3.0 port.
Since H1 supports internal 80W ACDC, there is a 5.5/2.5 port on the I/O shield plate beside the NUC onboard DC input jack to support internal AC adapter for NUC board. This way, no external AC adapter is needed if customer choose to use HDPLEX 80W ACDC or 200W ACDC for their NUC.
The PCIE slot can support one PCIE1 or PCIE4 expansion card by using M.2-PCIE adapter. In this case, customer need to use SATA port for SSD since M.2 is occupied.
The new H1 V3 and NUC kit is in tooling phase. It might take a while for them to be released.
NUC kit does not work on current H1 V2."