@Passerby is right, you can't test the interesting things about having multiple stations with a single Wifi device:
max total load would be the same as if a single station was trying to max out data transfer
Can't have different qualities of channels (and even less independent MIMO channel realizations) with a single antenna (or a single set of antennas)
It is quite normal since the 2.4GHz is… very sensitive to layout and changes of impedance.
First of all the uFL connector is horribly small but it always has two conductor, in the form of a microcoax cable. It is extremely small but there is a distinction between the center and the shielding.
The other issue is that the connector is precisely manufactured ...
This is an information sheet from Qualcomm on the MDM9207.
From the second page:
Integrated global positioning support for GPS, Beidou, GLONASS, and Galileo
Small package at 28nm LP to allow for optimized IoT form factors
Pre-integrated support for Qualcomm® VIVE™ Wi-Fi 1x1, 802.11ac featuring Qualcomm® MU | EFX MU-MIMO technology and BT 4.1 BLE