I have a v7 which has, I believe, a bit more open area near the driver devices.
I fabricated an interface from 3/8″sq AL stock, with necessary reliefs to avoid non-ground paths and drilled 4 M5 or M8 holes thru the ground PWB area to fasten the board, thru the interface, to a rather large surplus AMD CPU sink.
I have found no need for fans so far, but seldom run jobs longer than 20 mins.
The heat sink gets a little warm, the driver devices with attached dipsinks get to perhaps 105-110F, not bad at all.
Of course none of this is really sanctioned abuse of the tinyG board, but works for me; YRMV.
I can send some pics end of next week, traveling at the moment.