Here is an Ath10k wave2 development system where we bolted the radio heat sink to the bottom of the case. Four antennas on the back.
The large card is a Wave-2 MU-Mimo card. The card with the metal can on it is an Ath10k card by Doodle Labs.
The wave 2 card draws extra power from a Molex cable. It operates on 10-15W of system power. It needs thermal management and a heat-sink case with proper thermal contact is ideal.
Count all those antenna mountings!