There is an article from the c't magazine about this boad. Also mentioned the Armbian OS as an alternative OS to FA the ubuntu core.
https://www.heise.de/newsticker/meldung/NanoPi-NEO2-Upgrade-fuer-den-Kleinstrechner-3657847.html
(German language)
FriendlyArm released a NanoPI NEO specific heat sink:
http://www.friendlyarm.com/index.php?route=product/product&path=82&product_id=134
I am the owner of NanoPI NEO using the modified NanoPI M1 Armbian image of this thread.
I am not a expert of SBC design. But this board gets very hot. The sink has the same size like the SBC! Has the SBC a design problem, e.g. power supply? Or the CPU is so powerful and you must fix the heat problem by a approbiate heat sink or by software.